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  • Question 1 - In which part of the body is the nucleus of Meynert situated? ...

    Incorrect

    • In which part of the body is the nucleus of Meynert situated?

      Your Answer: Pineal body

      Correct Answer: Substantia innominata

      Explanation:

      The nucleus of Meynert, located in the substantia innominata of the basal forebrain beneath the thalamus and lentiform nucleus, is a cluster of neurons that serves as the primary source of acetylcholine in the brain. In Alzheimer’s disease, the nucleus of Meynert undergoes atrophy, resulting in a decrease in acetylcholine levels. This explains why cholinesterase inhibitors, which increase acetylcholine levels, are effective in treating Alzheimer’s.

      Alzheimer’s disease is characterized by both macroscopic and microscopic changes in the brain. Macroscopic changes include cortical atrophy, ventricular dilation, and depigmentation of the locus coeruleus. Microscopic changes include the presence of senile plaques, neurofibrillary tangles, gliosis, degeneration of the nucleus of Meynert, and Hirano bodies. Senile plaques are extracellular deposits of beta amyloid in the gray matter of the brain, while neurofibrillary tangles are intracellular inclusion bodies that consist primarily of hyperphosphorylated tau. Gliosis is marked by increases in activated microglia and reactive astrocytes near the sites of amyloid plaques. The nucleus of Meynert degenerates in Alzheimer’s, resulting in a decrease in acetylcholine in the brain. Hirano bodies are actin-rich, eosinophilic intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure and are regarded as a nonspecific manifestation of neuronal degeneration. These changes in the brain contribute to the cognitive decline and memory loss seen in Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
      17.5
      Seconds
  • Question 2 - What type of apraxia is indicated when a patient is given a pencil...

    Correct

    • What type of apraxia is indicated when a patient is given a pencil during a neurological examination and they attempt to use it to brush their teeth after looking at it for a minute?

      Your Answer: Ideomotor

      Explanation:

      The inability to carry out complex instructions is referred to as Ideational Apraxia, while the inability to perform previously learned actions with the appropriate tools is known as Ideomotor Apraxia.

      Apraxia: Understanding the Inability to Carry Out Learned Voluntary Movements

      Apraxia is a neurological condition that affects a person’s ability to carry out learned voluntary movements. It is important to note that this condition assumes that everything works and the person is not paralyzed. There are different types of apraxia, each with its own set of symptoms and characteristics.

      Limb kinetic apraxia is a type of apraxia that affects a person’s ability to make fine of delicate movements. This can include tasks such as buttoning a shirt of tying shoelaces.

      Ideomotor apraxia, on the other hand, is an inability to carry out learned tasks when given the necessary objects. For example, a person with ideomotor apraxia may try to write with a hairbrush instead of using it to brush their hair.

      Constructional apraxia affects a person’s ability to copy a picture of combine parts of something to form a whole. This can include tasks such as building a puzzle of drawing a picture.

      Ideational apraxia is an inability to follow a sequence of actions in the correct order. For example, a person with ideational apraxia may struggle to take a match out of a box and strike it with their left hand.

      Finally, oculomotor apraxia affects a person’s ability to control eye movements. This can make it difficult for them to track moving objects of read smoothly.

      Overall, apraxia can have a significant impact on a person’s ability to carry out everyday tasks. However, with the right support and treatment, many people with apraxia are able to improve their abilities and maintain their independence.

    • This question is part of the following fields:

      • Neurosciences
      16.7
      Seconds
  • Question 3 - A senior citizen visits your clinic and reports experiencing difficulty in seeing more...

    Correct

    • A senior citizen visits your clinic and reports experiencing difficulty in seeing more than one object at a time. As a result, they have been colliding with objects while moving around. What condition do you suspect?

      Your Answer: Bilateral parieto occipital lobe dysfunction

      Explanation:

      The observed symptoms in the patient are indicative of simultanagnosia, a condition that arises due to dysfunction in the parieto occipital lobes on both sides of the brain.

      Parietal Lobe Dysfunction: Types and Symptoms

      The parietal lobe is a part of the brain that plays a crucial role in processing sensory information and integrating it with other cognitive functions. Dysfunction in this area can lead to various symptoms, depending on the location and extent of the damage.

      Dominant parietal lobe dysfunction, often caused by a stroke, can result in Gerstmann’s syndrome, which includes finger agnosia, dyscalculia, dysgraphia, and right-left disorientation. Non-dominant parietal lobe dysfunction, on the other hand, can cause anosognosia, dressing apraxia, spatial neglect, and constructional apraxia.

      Bilateral damage to the parieto-occipital lobes, a rare condition, can lead to Balint’s syndrome, which is characterized by oculomotor apraxia, optic ataxia, and simultanagnosia. These symptoms can affect a person’s ability to shift gaze, interact with objects, and perceive multiple objects at once.

      In summary, parietal lobe dysfunction can manifest in various ways, and understanding the specific symptoms can help diagnose and treat the underlying condition.

    • This question is part of the following fields:

      • Neurosciences
      39.9
      Seconds
  • Question 4 - Which of the following is categorized as a projection tract in relation to...

    Incorrect

    • Which of the following is categorized as a projection tract in relation to white matter?

      Your Answer: Anterior commissure

      Correct Answer: Geniculocalcarine tract

      Explanation:

      White matter is the cabling that links different parts of the CNS together. There are three types of white matter cables: projection tracts, commissural tracts, and association tracts. Projection tracts connect higher centers of the brain with lower centers, commissural tracts connect the two hemispheres together, and association tracts connect regions of the same hemisphere. Some common tracts include the corticospinal tract, which connects the motor cortex to the brainstem and spinal cord, and the corpus callosum, which is the largest white matter fiber bundle connecting corresponding areas of cortex between the hemispheres. Other tracts include the cingulum, superior and inferior occipitofrontal fasciculi, and the superior and inferior longitudinal fasciculi.

    • This question is part of the following fields:

      • Neurosciences
      24.1
      Seconds
  • Question 5 - What is a true statement about sigma waves in relation to EEG? ...

    Correct

    • What is a true statement about sigma waves in relation to EEG?

      Your Answer: They are absent in familial fatal insomnia

      Explanation:

      Sigma waves are typically observed during stage 2 sleep and are considered a normal occurrence during sleep. They usually follow muscle twitches and are believed to help maintain a peaceful state during sleep. These waves are produced in the reticular nucleus of the thalamus and arise from the interplay between the thalamus and the cortex. However, in familial fatal insomnia (a prion disease), the absence of sigma waves is a characteristic feature.

      Electroencephalography

      Electroencephalography (EEG) is a clinical test that records the brain’s spontaneous electrical activity over a short period of time using multiple electrodes placed on the scalp. It is mainly used to rule out organic conditions and can help differentiate dementia from other disorders such as metabolic encephalopathies, CJD, herpes encephalitis, and non-convulsive status epilepticus. EEG can also distinguish possible psychotic episodes and acute confusional states from non-convulsive status epilepticus.

      Not all abnormal EEGs represent an underlying condition, and psychotropic medications can affect EEG findings. EEG abnormalities can also be triggered purposely by activation procedures such as hyperventilation, photic stimulation, certain drugs, and sleep deprivation.

      Specific waveforms are seen in an EEG, including delta, theta, alpha, sigma, beta, and gamma waves. Delta waves are found frontally in adults and posteriorly in children during slow wave sleep, and excessive amounts when awake may indicate pathology. Theta waves are generally seen in young children, drowsy and sleeping adults, and during meditation. Alpha waves are seen posteriorly when relaxed and when the eyes are closed, and are also seen in meditation. Sigma waves are bursts of oscillatory activity that occur in stage 2 sleep. Beta waves are seen frontally when busy of concentrating, and gamma waves are seen in advanced/very experienced meditators.

      Certain conditions are associated with specific EEG changes, such as nonspecific slowing in early CJD, low voltage EEG in Huntington’s, diffuse slowing in encephalopathy, and reduced alpha and beta with increased delta and theta in Alzheimer’s.

      Common epileptiform patterns include spikes, spike/sharp waves, and spike-waves. Medications can have important effects on EEG findings, with clozapine decreasing alpha and increasing delta and theta, lithium increasing all waveforms, lamotrigine decreasing all waveforms, and valproate having inconclusive effects on delta and theta and increasing beta.

      Overall, EEG is a useful tool in clinical contexts for ruling out organic conditions and differentiating between various disorders.

    • This question is part of the following fields:

      • Neurosciences
      20.9
      Seconds
  • Question 6 - What is the enzyme responsible for converting 5-hydroxytryptophan into serotonin? ...

    Correct

    • What is the enzyme responsible for converting 5-hydroxytryptophan into serotonin?

      Your Answer: L-aromatic amino acid decarboxylase

      Explanation:

      Serotonin: Synthesis and Breakdown

      Serotonin, also known as 5-Hydroxytryptamine (5-HT), is synthesized in the central nervous system (CNS) in the raphe nuclei located in the brainstem, as well as in the gastrointestinal (GI) tract in enterochromaffin cells. The amino acid L-tryptophan, obtained from the diet, is used to synthesize serotonin. L-tryptophan can cross the blood-brain barrier, but serotonin cannot.

      The transformation of L-tryptophan into serotonin involves two steps. First, hydroxylation to 5-hydroxytryptophan is catalyzed by tryptophan hydroxylase. Second, decarboxylation of 5-hydroxytryptophan to serotonin (5-hydroxytryptamine) is catalyzed by L-aromatic amino acid decarboxylase.

      Serotonin is taken up from the synapse by a monoamine transporter (SERT). Substances that block this transporter include MDMA, amphetamine, cocaine, TCAs, and SSRIs. Serotonin is broken down by monoamine oxidase (MAO) and then by aldehyde dehydrogenase to 5-Hydroxyindoleacetic acid (5-HIAA).

    • This question is part of the following fields:

      • Neurosciences
      30.9
      Seconds
  • Question 7 - What is a true statement about cerebrovascular accidents? ...

    Incorrect

    • What is a true statement about cerebrovascular accidents?

      Your Answer: Cerebral thrombosis is most common in people between the ages of 40-60

      Correct Answer: Cerebral infarction commonly occurs during sleep

      Explanation:

      It is widely acknowledged that women who have pre-existing cardiovascular disease should avoid taking oral contraceptives due to the increased risk of stroke and DVTs.

      Cerebrovascular accidents (CVA), also known as strokes, are defined by the World Health Organization as a sudden onset of focal neurological symptoms lasting more than 24 hours and presumed to be of vascular origin. Strokes can be caused by either infarction of hemorrhage, with infarction being more common. Hemorrhagic strokes tend to be more severe. Intracranial hemorrhage can be primary, caused mainly by hypertension, of subarachnoid, caused by the rupture of an aneurysm of angioma. Primary intracranial hemorrhage is most common in individuals aged 60-80 and often occurs during exertion. Infarction can be caused by thrombosis of embolism, with thrombosis being more common. Atherosclerosis, often caused by hypertension, is the main cause of infarction. CT scanning is the preferred diagnostic tool during the first 48 hours after a stroke as it can distinguish between infarcts and hemorrhages. Recovery from embolism is generally quicker and more complete than from thrombosis due to the availability of collateral channels.

    • This question is part of the following fields:

      • Neurosciences
      42.3
      Seconds
  • Question 8 - Which statement accurately describes the neurobiology of schizophrenia? ...

    Incorrect

    • Which statement accurately describes the neurobiology of schizophrenia?

      Your Answer:

      Correct Answer: Structural brain abnormalities are present at the onset of illness

      Explanation:

      Schizophrenia is a pathology that is characterized by a number of structural and functional brain alterations. Structural alterations include enlargement of the ventricles, reductions in total brain and gray matter volume, and regional reductions in the amygdala, parahippocampal gyrus, and temporal lobes. Antipsychotic treatment may be associated with gray matter loss over time, and even drug-naïve patients show volume reductions. Cerebral asymmetry is also reduced in affected individuals and healthy relatives. Functional alterations include diminished activation of frontal regions during cognitive tasks and increased activation of temporal regions during hallucinations. These findings suggest that schizophrenia is associated with both macroscopic and functional changes in the brain.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 9 - Which of the following symptoms is not associated with Gerstmann's syndrome? ...

    Incorrect

    • Which of the following symptoms is not associated with Gerstmann's syndrome?

      Your Answer:

      Correct Answer: Prosopagnosia

      Explanation:

      Gerstmann’s Syndrome: Symptoms and Brain Lesions

      Gerstmann’s syndrome is a condition that is characterized by several symptoms, including dyscalculia, dysgraphia, finger agnosia, and right-left disorientation. Patients with this syndrome have been found to have lesions in areas such as the left frontal posterior, left parietal, temporal, and occipital lobes. The left angular gyrus, which is located at the junction of the temporal, occipital, and parietal lobes, seems to be the main area of overlap. Although the function of the angular gyrus is not well understood, it is believed to be involved in various functions such as calculation, spatial reasoning, understanding of ordinal concepts, and comprehension of metaphors.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 10 - Which structure is not included in the neocortex? ...

    Incorrect

    • Which structure is not included in the neocortex?

      Your Answer:

      Correct Answer: Caudate nucleus

      Explanation:

      The Cerebral Cortex and Neocortex

      The cerebral cortex is the outermost layer of the cerebral hemispheres and is composed of three parts: the archicortex, paleocortex, and neocortex. The neocortex accounts for 90% of the cortex and is involved in higher functions such as thought and language. It is divided into 6-7 layers, with two main cell types: pyramidal cells and nonpyramidal cells. The surface of the neocortex is divided into separate areas, each given a number by Brodmann (e.g. Brodmann’s area 17 is the primary visual cortex). The surface is folded to increase surface area, with grooves called sulci and ridges called gyri. The neocortex is responsible for higher cognitive functions and is essential for human consciousness.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 11 - What is another term for 'intrinsic activity' when referring to drug/receptor interactions? ...

    Incorrect

    • What is another term for 'intrinsic activity' when referring to drug/receptor interactions?

      Your Answer:

      Correct Answer: Efficacy

      Explanation:

      Efficacy, also referred to as intrinsic activity, pertains to a drug’s capacity to produce a reaction upon binding to a receptor.

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 12 - What is a true statement about multisystem atrophy? ...

    Incorrect

    • What is a true statement about multisystem atrophy?

      Your Answer:

      Correct Answer: Associated Parkinson's symptoms respond poorly to levodopa

      Explanation:

      Parkinson plus syndromes, including multisystem atrophy, exhibit a limited efficacy towards Parkinson’s treatment, such as levodopa.

      Multisystem Atrophy: A Parkinson Plus Syndrome

      Multisystem atrophy is a type of Parkinson plus syndrome that is characterized by three main features: Parkinsonism, autonomic failure, and cerebellar ataxia. It can present in three different ways, including Shy-Drager Syndrome, Striatonigral degeneration, and Olivopontocerebellar atrophy, each with varying degrees of the three main features.

      Macroscopic features of multisystem atrophy include pallor of the substantia nigra, greenish discoloration and atrophy of the putamen, and cerebellar atrophy. Microscopic features include the presence of Papp-Lantos bodies, which are alpha-synuclein inclusions found in oligodendrocytes in the substantia nigra, cerebellum, and basal ganglia.

      Overall, multisystem atrophy is a complex and debilitating condition that affects multiple systems in the body, leading to a range of symptoms and challenges for patients and their caregivers.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 13 - Which enzyme is responsible for the conversion of tyrosine to dihydroxyphenylalanine? ...

    Incorrect

    • Which enzyme is responsible for the conversion of tyrosine to dihydroxyphenylalanine?

      Your Answer:

      Correct Answer: Tyrosine hydroxylase

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 14 - Which area is believed to have the primary role in psychosis due to...

    Incorrect

    • Which area is believed to have the primary role in psychosis due to an overabundance of dopaminergic activity?

      Your Answer:

      Correct Answer: Striatum

      Explanation:

      The Dopamine Hypothesis is a theory that suggests that dopamine and dopaminergic mechanisms are central to schizophrenia. This hypothesis was developed based on observations that antipsychotic drugs provide at least some degree of D2-type dopamine receptor blockade and that it is possible to induce a psychotic episode in healthy subjects with pharmacological dopamine agonists. The hypothesis was further strengthened by the finding that antipsychotic drugs’ clinical effectiveness was directly related to their affinity for dopamine receptors. Initially, the belief was that the problem related to an excess of dopamine in the brain. However, later studies showed that the relationship between hypofrontality and low cerebrospinal fluid (CSF) dopamine metabolite levels indicates low frontal dopamine levels. Thus, there was a move from a one-sided dopamine hypothesis explaining all facets of schizophrenia to a regionally specific prefrontal hypodopaminergia and a subcortical hyperdopaminergia. In summary, psychosis appears to result from excessive dopamine activity in the striatum, while the negative symptoms seen in schizophrenia appear to result from too little dopamine activity in the frontal lobe. Antipsychotic medications appear to help by countering the effects of increased dopamine by blocking postsynaptic D2 receptors in the striatum.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 15 - The nomenclature of PrPSc, the disease-linked form of mammalian prion protein PrP, was...

    Incorrect

    • The nomenclature of PrPSc, the disease-linked form of mammalian prion protein PrP, was derived from a long-observed prion disease in which animal?

      Your Answer:

      Correct Answer: Sheep

      Explanation:

      The term PrPSc originated from scrapie, a prion disease that affects sheep. In humans, the normal isoform of prion protein is PrPC, while the abnormal form is known as PrPres (protease-resistant) of PrPSc. Scrapie has been observed in sheep for over 300 years, while BSE in cattle was only identified in the 1980s. Feline spongiform encephalopathy (FSE) is a prion disease that affects cats, and Chronic wasting disease (CWD) is a similar condition that affects deer.

    • This question is part of the following fields:

      • Neurosciences
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      Seconds
  • Question 16 - What is the most likely diagnosis when an MRI shows high signal in...

    Incorrect

    • What is the most likely diagnosis when an MRI shows high signal in the medial aspects of both thalami that is bilateral and symmetrical?

      Your Answer:

      Correct Answer: Variant CJD

      Explanation:

      The pulvinar sign seen on radiological imaging can indicate several possible conditions, including Alper’s Syndrome, cat-scratch disease, and post-infectious encephalitis. It may also be present in cases of M/V2 subtype of sporadic CJD, thalamic infarctions, and top-of-the-basilar ischemia. However, when considering vCJD, the pulvinar sign should be evaluated in the appropriate clinical context.

      Creutzfeldt-Jakob Disease: Differences between vCJD and CJD

      Creutzfeldt-Jakob Disease (CJD) is a prion disease that includes scrapie, BSE, and Kuru. However, there are important differences between sporadic (also known as classic) CJD and variant CJD. The table below summarizes these differences.

      vCJD:
      – Longer duration from onset of symptoms to death (a year of more)
      – Presents with psychiatric and behavioral symptoms before neurological symptoms
      – MRI shows pulvinar sign
      – EEG shows generalized slowing
      – Originates from infected meat products
      – Affects younger people (age 25-30)

      CJD:
      – Shorter duration from onset of symptoms to death (a few months)
      – Presents with neurological symptoms
      – MRI shows bilateral anterior basal ganglia high signal
      – EEG shows biphasic and triphasic waves 1-2 per second
      – Originates from genetic mutation (bad luck)
      – Affects older people (age 55-65)

      Overall, understanding the differences between vCJD and CJD is important for diagnosis and treatment.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 17 - Which of the following lower brain structures can cause either decreased or increased...

    Incorrect

    • Which of the following lower brain structures can cause either decreased or increased appetite when damaged?

      Your Answer:

      Correct Answer: Hypothalamus

      Explanation:

      Hunger and thirst are regulated by the hypothalamus, while emotional responses and perceptions of others’ emotions are controlled by the amygdala. The brainstem is responsible for arousal, while the cerebellum controls voluntary movement and balance. The medulla, on the other hand, controls breathing and heartbeat.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 18 - How can association tracts be defined in relation to white matter? ...

    Incorrect

    • How can association tracts be defined in relation to white matter?

      Your Answer:

      Correct Answer: Cingulum

      Explanation:

      White matter is the cabling that links different parts of the CNS together. There are three types of white matter cables: projection tracts, commissural tracts, and association tracts. Projection tracts connect higher centers of the brain with lower centers, commissural tracts connect the two hemispheres together, and association tracts connect regions of the same hemisphere. Some common tracts include the corticospinal tract, which connects the motor cortex to the brainstem and spinal cord, and the corpus callosum, which is the largest white matter fiber bundle connecting corresponding areas of cortex between the hemispheres. Other tracts include the cingulum, superior and inferior occipitofrontal fasciculi, and the superior and inferior longitudinal fasciculi.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 19 - What is the most effective method for distinguishing between Alzheimer's disease and Lewy...

    Incorrect

    • What is the most effective method for distinguishing between Alzheimer's disease and Lewy body dementia?

      Your Answer:

      Correct Answer: Dat scan

      Explanation:

      It’s important to note that DaT-SCAN and SPECT are not the same thing. DaT-SCAN specifically refers to the radioactive isotope called Ioflupane, which is utilized in the creation of a SPECT image.

      Alzheimer’s disease can be differentiated from healthy older individuals by using SPECT imaging to detect temporal and parietal hypoperfusion, according to studies such as one conducted by W. Jagust in 2001. Additionally, SPECT imaging has proven to be a useful tool in distinguishing between Alzheimer’s disease and Lewy body dementia, as demonstrated in a study by Vaamonde-Gamo in 2005. The image provided shows a SPECT scan of a patient with Alzheimer’s disease compared to one with Lewy body dementia, with the latter showing lower perfusion in the occipital cortex and the former showing lower perfusion in medial temporal areas.

    • This question is part of the following fields:

      • Neurosciences
      0
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  • Question 20 - What is a true statement about cerebrovascular accidents? ...

    Incorrect

    • What is a true statement about cerebrovascular accidents?

      Your Answer:

      Correct Answer: Cerebral infarction commonly occurs during sleep

      Explanation:

      During sleep, strokes are more likely to occur as blood pressure decreases and areas of the brain with poor blood flow (caused by arterial damage in arteriopaths) become oxygen-deprived. Women with pre-existing cardiovascular disease should avoid taking oral contraceptives as they can raise the risk of stroke and DVTs.

      Cerebrovascular accidents (CVA), also known as strokes, are defined by the World Health Organization as a sudden onset of focal neurological symptoms lasting more than 24 hours and presumed to be of vascular origin. Strokes can be caused by either infarction of hemorrhage, with infarction being more common. Hemorrhagic strokes tend to be more severe. Intracranial hemorrhage can be primary, caused mainly by hypertension, of subarachnoid, caused by the rupture of an aneurysm of angioma. Primary intracranial hemorrhage is most common in individuals aged 60-80 and often occurs during exertion. Infarction can be caused by thrombosis of embolism, with thrombosis being more common. Atherosclerosis, often caused by hypertension, is the main cause of infarction. CT scanning is the preferred diagnostic tool during the first 48 hours after a stroke as it can distinguish between infarcts and hemorrhages. Recovery from embolism is generally quicker and more complete than from thrombosis due to the availability of collateral channels.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 21 - Which type of injury of damage typically leads to utilization behaviour? ...

    Incorrect

    • Which type of injury of damage typically leads to utilization behaviour?

      Your Answer:

      Correct Answer: Frontal lobe

      Explanation:

      Abnormal Motor Behaviours Associated with Utilization Behaviour

      Utilization behaviour (UB) is a condition where patients exhibit exaggerated and inappropriate motor responses to environmental cues and objects. This behaviour is automatic and instrumentally correct, but not contextually appropriate. For instance, a patient may start brushing their teeth when presented with a toothbrush, even in a setting where it is not expected. UB is caused by frontal lobe lesions that result in a loss of inhibitory control.

      Other motor abnormalities associated with UB include imitation behaviour, where patients tend to imitate the examiner’s behaviour, and the alien hand sign, where patients experience bizarre hand movements that they cannot control. Manual groping behaviour is also observed, where patients automatically manipulate objects placed in front of them. The grasp reflex, which is normal in infants, should not be present in children and adults. It is an automatic tendency to grip objects of stimuli, such as the examiner’s hand.

      Environmental Dependency Syndrome is another condition associated with UB. It describes deficits in personal control of action and an overreliance on social and physical environmental stimuli to guide behaviour in a social context. For example, a patient may start commenting on pictures in an examiner’s office, believing it to be an art gallery.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 22 - What condition has been associated with decreased small interneurons in cortical layer II...

    Incorrect

    • What condition has been associated with decreased small interneurons in cortical layer II of the prefrontal cortex, which are believed to be related to the GABA system?

      Your Answer:

      Correct Answer: Schizophrenia

      Explanation:

      The key to answering this question is identifying that it pertains to the prefrontal cortex, which is strongly linked to schizophrenia. Other conditions that are associated with abnormalities in this region include ADHD and bipolar disorder. Schizophrenia is characterized by changes in GABA function, including both release and uptake. Additionally, a decrease in small interneurons in cortical layer II of the prefrontal cortex is believed to contribute to these alterations. Sedvall’s 2002 work on the pathophysiological mechanisms of schizophrenia provides further insight into these issues.

      Schizophrenia is a pathology that is characterized by a number of structural and functional brain alterations. Structural alterations include enlargement of the ventricles, reductions in total brain and gray matter volume, and regional reductions in the amygdala, parahippocampal gyrus, and temporal lobes. Antipsychotic treatment may be associated with gray matter loss over time, and even drug-naïve patients show volume reductions. Cerebral asymmetry is also reduced in affected individuals and healthy relatives. Functional alterations include diminished activation of frontal regions during cognitive tasks and increased activation of temporal regions during hallucinations. These findings suggest that schizophrenia is associated with both macroscopic and functional changes in the brain.

    • This question is part of the following fields:

      • Neurosciences
      0
      Seconds
  • Question 23 - The patient's complaint of being unable to identify objects in their hand without...

    Incorrect

    • The patient's complaint of being unable to identify objects in their hand without visual confirmation is an instance of what?

      Your Answer:

      Correct Answer: Astereognosia

      Explanation:

      Agnosia is a condition where a person loses the ability to recognize objects, persons, sounds, shapes, of smells, despite having no significant memory loss of defective senses. There are different types of agnosia, such as prosopagnosia (inability to recognize familiar faces), anosognosia (inability to recognize one’s own condition/illness), autotopagnosia (inability to orient parts of the body), phonagnosia (inability to recognize familiar voices), simultanagnosia (inability to appreciate two objects in the visual field at the same time), and astereoagnosia (inability to recognize objects by touch).

    • This question is part of the following fields:

      • Neurosciences
      0
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  • Question 24 - Which receptor's agonist effect is most likely responsible for anorgasmia caused by SSRIs?...

    Incorrect

    • Which receptor's agonist effect is most likely responsible for anorgasmia caused by SSRIs?

      Your Answer:

      Correct Answer: 5HT2C

      Explanation:

      As an AI language model, I cannot provide a response without knowing the context of the rewrite you are referring to. Please provide more information of context so that I can assist you better.

      Serotonin (5-hydroxytryptamine, 5-HT) receptors are primarily G protein receptors, except for 5-HT3, which is a ligand-gated receptor. It is important to remember that 5-HT3 is most commonly associated with nausea. Additionally, 5-HT7 is linked to circadian rhythms. The stimulation of 5-HT2 receptors is believed to be responsible for the side effects of insomnia, agitation, and sexual dysfunction that are associated with the use of selective serotonin reuptake inhibitors (SSRIs).

    • This question is part of the following fields:

      • Neurosciences
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  • Question 25 - Which condition is most commonly associated with the presence of eosinophilic cytoplasmic inclusion...

    Incorrect

    • Which condition is most commonly associated with the presence of eosinophilic cytoplasmic inclusion bodies containing alpha-synuclein?

      Your Answer:

      Correct Answer: Lewy body dementia

      Explanation:

      Lewy body dementia is a neurodegenerative disorder that is characterized by both macroscopic and microscopic changes in the brain. Macroscopically, there is cerebral atrophy, but it is less marked than in Alzheimer’s disease, and the brain weight is usually in the normal range. There is also pallor of the substantia nigra and the locus coeruleus, which are regions of the brain that produce dopamine and norepinephrine, respectively.

      Microscopically, Lewy body dementia is characterized by the presence of intracellular protein accumulations called Lewy bodies. The major component of a Lewy body is alpha synuclein, and as they grow, they start to draw in other proteins such as ubiquitin. Lewy bodies are also found in Alzheimer’s disease, but they tend to be in the amygdala. They can also be found in healthy individuals, although it has been suggested that these may be pre-clinical cases of dementia with Lewy bodies. Lewy bodies are also found in other neurodegenerative disorders such as progressive supranuclear palsy, corticobasal degeneration, and multiple system atrophy.

      In Lewy body dementia, Lewy bodies are mainly found within the brainstem, but they are also found in non-brainstem regions such as the amygdaloid nucleus, parahippocampal gyrus, cingulate cortex, and cerebral neocortex. Classic brainstem Lewy bodies are spherical intraneuronal cytoplasmic inclusions, characterized by hyaline eosinophilic cores, concentric lamellar bands, narrow pale halos, and immunoreactivity for alpha synuclein and ubiquitin. In contrast, cortical Lewy bodies typically lack a halo.

      Most brains with Lewy body dementia also show some plaques and tangles, although in most instances, the lesions are not nearly as severe as in Alzheimer’s disease. Neuronal loss and gliosis are usually restricted to brainstem regions, particularly the substantia nigra and locus ceruleus.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 26 - What condition is identified by the combination of Parkinsonism, cerebellar ataxia, and autonomic...

    Incorrect

    • What condition is identified by the combination of Parkinsonism, cerebellar ataxia, and autonomic failure?

      Your Answer:

      Correct Answer: Multisystem atrophy

      Explanation:

      Multisystem Atrophy: A Parkinson Plus Syndrome

      Multisystem atrophy is a type of Parkinson plus syndrome that is characterized by three main features: Parkinsonism, autonomic failure, and cerebellar ataxia. It can present in three different ways, including Shy-Drager Syndrome, Striatonigral degeneration, and Olivopontocerebellar atrophy, each with varying degrees of the three main features.

      Macroscopic features of multisystem atrophy include pallor of the substantia nigra, greenish discoloration and atrophy of the putamen, and cerebellar atrophy. Microscopic features include the presence of Papp-Lantos bodies, which are alpha-synuclein inclusions found in oligodendrocytes in the substantia nigra, cerebellum, and basal ganglia.

      Overall, multisystem atrophy is a complex and debilitating condition that affects multiple systems in the body, leading to a range of symptoms and challenges for patients and their caregivers.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 27 - Which condition is most likely to be associated with diffuse delta and theta...

    Incorrect

    • Which condition is most likely to be associated with diffuse delta and theta waves on an EEG?

      Your Answer:

      Correct Answer: Metabolic encephalopathy

      Explanation:

      Delta waves are typically observed during stages III and IV of deep sleep and their presence outside of these stages can indicate diffuse slowing and encephalopathy.

      Electroencephalography

      Electroencephalography (EEG) is a clinical test that records the brain’s spontaneous electrical activity over a short period of time using multiple electrodes placed on the scalp. It is mainly used to rule out organic conditions and can help differentiate dementia from other disorders such as metabolic encephalopathies, CJD, herpes encephalitis, and non-convulsive status epilepticus. EEG can also distinguish possible psychotic episodes and acute confusional states from non-convulsive status epilepticus.

      Not all abnormal EEGs represent an underlying condition, and psychotropic medications can affect EEG findings. EEG abnormalities can also be triggered purposely by activation procedures such as hyperventilation, photic stimulation, certain drugs, and sleep deprivation.

      Specific waveforms are seen in an EEG, including delta, theta, alpha, sigma, beta, and gamma waves. Delta waves are found frontally in adults and posteriorly in children during slow wave sleep, and excessive amounts when awake may indicate pathology. Theta waves are generally seen in young children, drowsy and sleeping adults, and during meditation. Alpha waves are seen posteriorly when relaxed and when the eyes are closed, and are also seen in meditation. Sigma waves are bursts of oscillatory activity that occur in stage 2 sleep. Beta waves are seen frontally when busy of concentrating, and gamma waves are seen in advanced/very experienced meditators.

      Certain conditions are associated with specific EEG changes, such as nonspecific slowing in early CJD, low voltage EEG in Huntington’s, diffuse slowing in encephalopathy, and reduced alpha and beta with increased delta and theta in Alzheimer’s.

      Common epileptiform patterns include spikes, spike/sharp waves, and spike-waves. Medications can have important effects on EEG findings, with clozapine decreasing alpha and increasing delta and theta, lithium increasing all waveforms, lamotrigine decreasing all waveforms, and valproate having inconclusive effects on delta and theta and increasing beta.

      Overall, EEG is a useful tool in clinical contexts for ruling out organic conditions and differentiating between various disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 28 - A 42 year old, overweight woman presents with recurring episodes of one-sided vision...

    Incorrect

    • A 42 year old, overweight woman presents with recurring episodes of one-sided vision loss accompanied by pain over the last 24 months. She is curious if her use of fluoxetine, which you prescribed for her depression, could be a contributing factor. What is your primary suspicion regarding her symptoms?

      Your Answer:

      Correct Answer: Multiple sclerosis

      Explanation:

      The symptoms experienced by the woman are most indicative of optic neuritis, which is characterized by inflammation of the optic nerve where it connects to the eye. This typically results in temporary loss of vision in one eye, accompanied by pain during eye movement. Optic neuritis is commonly associated with multiple sclerosis. It is unlikely that the woman is experiencing an arterial occlusion, as this would cause permanent and painless vision loss. A pituitary adenoma would affect both eyes and result in permanent vision loss. The possibility of a somatoform disorder is unlikely, as the women’s symptoms align with a recognized medical diagnosis. Endophthalmitis is a serious condition that can cause permanent vision loss and requires immediate medical attention.

      Multiple Sclerosis: An Overview

      Multiple sclerosis is a neurological disorder that is classified into three categories: primary progressive, relapsing-remitting, and secondary progressive. Primary progressive multiple sclerosis affects 5-10% of patients and is characterized by a steady progression with no remissions. Relapsing-remitting multiple sclerosis affects 20-30% of patients and presents with a relapsing-remitting course but does not lead to serious disability. Secondary progressive multiple sclerosis affects 60% of patients and initially presents with a relapsing-remitting course but is then followed by a phase of progressive deterioration.

      The disorder typically begins between the ages of 20 and 40 and is characterized by multiple demyelinating lesions that have a preference for the optic nerves, cerebellum, brainstem, and spinal cord. Patients with multiple sclerosis present with a variety of neurological signs that reflect the presence and distribution of plaques. Ocular features of multiple sclerosis include optic neuritis, internuclear ophthalmoplegia, and ocular motor cranial neuropathy.

      Multiple sclerosis is more common in women than in men and is seen with increasing frequency as the distance from the equator increases. It is believed to be caused by a combination of genetic and environmental factors, with monozygotic concordance at 25%. Overall, multiple sclerosis is a predominantly white matter disease that can have a significant impact on a patient’s quality of life.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 29 - A child comes to the clinic, they say hello and take a seat....

    Incorrect

    • A child comes to the clinic, they say hello and take a seat. You ask them how their day was to which they answer 'good'. They are then asked to name their favorite animal to which they answer dog. They are then asked what sound a cat makes and they answer woof. They are then asked what color the sky is and they answer green. What sign do they exhibit?

      Your Answer:

      Correct Answer: Perseveration

      Explanation:

      Perseveration: The Clinical Symptoms in Chronic Schizophrenia and Organic Dementia

      Perseveration is a common behavior observed in patients with organic brain involvement. It is characterized by the conscious continuation of an act of an idea. This behavior is frequently seen in patients with delirium, epilepsy, dementia, schizophrenia, and normal individuals under extreme fatigue of drug-induced states.

      In chronic schizophrenia and organic dementia, perseveration is a prominent symptom. Patients with these conditions tend to repeat the same words, phrases, of actions over and over again, even when it is no longer appropriate of relevant to the situation. This behavior can be frustrating for caregivers and family members, and it can also interfere with the patient’s ability to communicate effectively.

      In schizophrenia, perseveration is often associated with disorganized thinking and speech. Patients may jump from one topic to another without any logical connection, and they may repeat the same words of phrases in an attempt to express their thoughts. In organic dementia, perseveration is a sign of cognitive decline and memory impairment. Patients may repeat the same stories of questions, forgetting that they have already asked of answered them.

      Overall, perseveration is a common symptom in patients with organic brain involvement, and it can have a significant impact on their daily functioning and quality of life. Understanding this behavior is essential for effective management and treatment of these conditions.

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      • Neurosciences
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  • Question 30 - Which area of the brain is responsible for causing hemiballismus when it is...

    Incorrect

    • Which area of the brain is responsible for causing hemiballismus when it is damaged?

      Your Answer:

      Correct Answer: Subthalamic nucleus

      Explanation:

      Hemiballismus is an uncommon condition that arises following a stroke affecting the basal ganglia, particularly the subthalamic nucleus. It is typically identified by uncontrolled flinging movements of the limbs, which can be forceful and have a broad range of motion. These movements are unpredictable and ongoing, and may affect either the proximal or distal muscles on one side of the body.

      The Basal Ganglia: Functions and Disorders

      The basal ganglia are a group of subcortical structures that play a crucial role in controlling movement and some cognitive processes. The components of the basal ganglia include the striatum (caudate, putamen, nucleus accumbens), subthalamic nucleus, globus pallidus, and substantia nigra (divided into pars compacta and pars reticulata). The putamen and globus pallidus are collectively referred to as the lenticular nucleus.

      The basal ganglia are connected in a complex loop, with the cortex projecting to the striatum, the striatum to the internal segment of the globus pallidus, the internal segment of the globus pallidus to the thalamus, and the thalamus back to the cortex. This loop is responsible for regulating movement and cognitive processes.

      However, problems with the basal ganglia can lead to several conditions. Huntington’s chorea is caused by degeneration of the caudate nucleus, while Wilson’s disease is characterized by copper deposition in the basal ganglia. Parkinson’s disease is associated with degeneration of the substantia nigra, and hemiballism results from damage to the subthalamic nucleus.

      In summary, the basal ganglia are a crucial part of the brain that regulate movement and some cognitive processes. Disorders of the basal ganglia can lead to significant neurological conditions that affect movement and other functions.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 31 - What is the precursor amino acid for dopamine synthesis? ...

    Incorrect

    • What is the precursor amino acid for dopamine synthesis?

      Your Answer:

      Correct Answer: Tyrosine

      Explanation:

      Tyrosine is converted to L-DOPA by the enzyme tyrosine hydroxylase. L-DOPA is then converted to dopamine by the enzyme dopa decarboxylase.

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 32 - What is the most effective tool to use when suspecting a brain hemorrhage...

    Incorrect

    • What is the most effective tool to use when suspecting a brain hemorrhage in an emergency situation?

      Your Answer:

      Correct Answer: CT

      Explanation:

      Neuroimaging techniques can be divided into structural and functional types, although this distinction is becoming less clear as new techniques emerge. Structural techniques include computed tomography (CT) and magnetic resonance imaging (MRI), which use x-rays and magnetic fields, respectively, to produce images of the brain’s structure. Functional techniques, on the other hand, measure brain activity by detecting changes in blood flow of oxygen consumption. These include functional MRI (fMRI), emission tomography (PET and SPECT), perfusion MRI (pMRI), and magnetic resonance spectroscopy (MRS). Some techniques, such as diffusion tensor imaging (DTI), combine both structural and functional information to provide a more complete picture of the brain’s anatomy and function. DTI, for example, uses MRI to estimate the paths that water takes as it diffuses through white matter, allowing researchers to visualize white matter tracts.

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      • Neurosciences
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  • Question 33 - Which cranial nerve is solely responsible for either sensory of motor functions and...

    Incorrect

    • Which cranial nerve is solely responsible for either sensory of motor functions and does not have a combination of both?

      Your Answer:

      Correct Answer: Abducens

      Explanation:

      Overview of Cranial Nerves and Their Functions

      The cranial nerves are a complex system of nerves that originate from the brain and control various functions of the head and neck. There are twelve cranial nerves, each with a specific function and origin. The following table provides a simplified overview of the cranial nerves, including their origin, skull exit, modality, and functions.

      The first cranial nerve, the olfactory nerve, originates from the telencephalon and exits through the cribriform plate. It is a sensory nerve that controls the sense of smell. The second cranial nerve, the optic nerve, originates from the diencephalon and exits through the optic foramen. It is a sensory nerve that controls vision.

      The third cranial nerve, the oculomotor nerve, originates from the midbrain and exits through the superior orbital fissure. It is a motor nerve that controls eye movement, pupillary constriction, and lens accommodation. The fourth cranial nerve, the trochlear nerve, also originates from the midbrain and exits through the superior orbital fissure. It is a motor nerve that controls eye movement.

      The fifth cranial nerve, the trigeminal nerve, originates from the pons and exits through different foramina depending on the division. It is a mixed nerve that controls chewing and sensation of the anterior 2/3 of the scalp. It also tenses the tympanic membrane to dampen loud noises.

      The sixth cranial nerve, the abducens nerve, originates from the pons and exits through the superior orbital fissure. It is a motor nerve that controls eye movement. The seventh cranial nerve, the facial nerve, also originates from the pons and exits through the internal auditory canal. It is a mixed nerve that controls facial expression, taste of the anterior 2/3 of the tongue, and tension on the stapes to dampen loud noises.

      The eighth cranial nerve, the vestibulocochlear nerve, originates from the pons and exits through the internal auditory canal. It is a sensory nerve that controls hearing. The ninth cranial nerve, the glossopharyngeal nerve, originates from the medulla and exits through the jugular foramen. It is a mixed nerve that controls taste of the posterior 1/3 of the tongue, elevation of the larynx and pharynx, and swallowing.

      The tenth cranial nerve, the vagus nerve, also originates from the medulla and exits through the jugular foramen. It is a mixed nerve that controls swallowing, voice production, and parasympathetic supply to nearly all thoracic and abdominal viscera. The eleventh cranial nerve, the accessory nerve, originates from the medulla and exits through the jugular foramen. It is a motor nerve that controls shoulder shrugging and head turning.

      The twelfth cranial nerve, the hypoglossal nerve, originates from the medulla and exits through the hypoglossal canal. It is a motor nerve that controls tongue movement. Overall, the cranial nerves play a crucial role in controlling various functions of the head and neck, and any damage of dysfunction can have significant consequences.

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  • Question 34 - What gas functions as a neurotransmitter? ...

    Incorrect

    • What gas functions as a neurotransmitter?

      Your Answer:

      Correct Answer: Carbon monoxide

      Explanation:

      It’s important to differentiate between nitrogen and nitrous oxide, as they have distinct properties. Nitrogen is not a neurotransmitter, while nitrous oxide is sometimes used for its anesthetic and analgesic effects.

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

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      • Neurosciences
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  • Question 35 - What is the most accurate way to describe the speech of an individual...

    Incorrect

    • What is the most accurate way to describe the speech of an individual with Broca's aphasia?

      Your Answer:

      Correct Answer: Non fluent aphasia

      Explanation:

      Broca’s aphasia is also known as non-fluent aphasia, while Wernicke’s aphasia is referred to as fluent aphasia.

      Broca’s and Wernicke’s are two types of expressive dysphasia, which is characterized by difficulty producing speech despite intact comprehension. Dysarthria is a type of expressive dysphasia caused by damage to the speech production apparatus, while Broca’s aphasia is caused by damage to the area of the brain responsible for speech production, specifically Broca’s area located in Brodmann areas 44 and 45. On the other hand, Wernicke’s aphasia is a type of receptive of fluent aphasia caused by damage to the comprehension of speech, while the actual production of speech remains normal. Wernicke’s area is located in the posterior part of the superior temporal gyrus in the dominant hemisphere, within Brodmann area 22.

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  • Question 36 - Which area of the central nervous system is indicated by a positive outcome...

    Incorrect

    • Which area of the central nervous system is indicated by a positive outcome in the finger-to-nose test?

      Your Answer:

      Correct Answer: Cerebellum

      Explanation:

      The finger-nose test requires the patient to touch their nose and then the examiner’s finger consecutively. If the patient is unable to perform this task, it indicates motor dysmetria, which is a lack of coordination and may indicate a cerebellar injury.

      Cerebellar Dysfunction: Symptoms and Signs

      Cerebellar dysfunction is a condition that affects the cerebellum, a part of the brain responsible for coordinating movement and balance. The symptoms and signs of cerebellar dysfunction include ataxia, intention tremor, nystagmus, broad-based gait, slurred speech, dysdiadochokinesis, and dysmetria (lack of finger-nose coordination).

      Ataxia refers to the lack of coordination of voluntary movements, resulting in unsteady gait, difficulty with balance, and clumsiness. Intention tremor is a type of tremor that occurs during voluntary movements, such as reaching for an object. Nystagmus is an involuntary movement of the eyes, characterized by rapid, jerky movements.

      Broad-based gait refers to a wide stance while walking, which is often seen in individuals with cerebellar dysfunction. Slurred speech, also known as dysarthria, is a common symptom of cerebellar dysfunction, which affects the ability to articulate words clearly. Dysdiadochokinesis is the inability to perform rapid alternating movements, such as tapping the fingers on the palm of the hand.

      Dysmetria refers to the inability to accurately judge the distance and direction of movements, resulting in errors in reaching for objects of touching the nose with the finger. These symptoms and signs of cerebellar dysfunction can be caused by a variety of conditions, including stroke, multiple sclerosis, and alcoholism. Treatment depends on the underlying cause and may include medications, physical therapy, and surgery.

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  • Question 37 - Are athetoid movements commonly associated with basal ganglia dysfunction rather than cerebellar dysfunction?...

    Incorrect

    • Are athetoid movements commonly associated with basal ganglia dysfunction rather than cerebellar dysfunction?

      Your Answer:

      Correct Answer: Athetoid movements

      Explanation:

      Abnormal movements known as athetoid movements are commonly associated with issues in the basal ganglia.

      Cerebellar Dysfunction: Symptoms and Signs

      Cerebellar dysfunction is a condition that affects the cerebellum, a part of the brain responsible for coordinating movement and balance. The symptoms and signs of cerebellar dysfunction include ataxia, intention tremor, nystagmus, broad-based gait, slurred speech, dysdiadochokinesis, and dysmetria (lack of finger-nose coordination).

      Ataxia refers to the lack of coordination of voluntary movements, resulting in unsteady gait, difficulty with balance, and clumsiness. Intention tremor is a type of tremor that occurs during voluntary movements, such as reaching for an object. Nystagmus is an involuntary movement of the eyes, characterized by rapid, jerky movements.

      Broad-based gait refers to a wide stance while walking, which is often seen in individuals with cerebellar dysfunction. Slurred speech, also known as dysarthria, is a common symptom of cerebellar dysfunction, which affects the ability to articulate words clearly. Dysdiadochokinesis is the inability to perform rapid alternating movements, such as tapping the fingers on the palm of the hand.

      Dysmetria refers to the inability to accurately judge the distance and direction of movements, resulting in errors in reaching for objects of touching the nose with the finger. These symptoms and signs of cerebellar dysfunction can be caused by a variety of conditions, including stroke, multiple sclerosis, and alcoholism. Treatment depends on the underlying cause and may include medications, physical therapy, and surgery.

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      • Neurosciences
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  • Question 38 - What structure is situated in the middle cranial fossa? ...

    Incorrect

    • What structure is situated in the middle cranial fossa?

      Your Answer:

      Correct Answer: Foramen lacerum

      Explanation:

      The foramen lacerum is a opening located in the middle cranial fossa at the base of the skull.

      Cranial Fossae and Foramina

      The cranium is divided into three regions known as fossae, each housing different cranial lobes. The anterior cranial fossa contains the frontal lobes and includes the frontal and ethmoid bones, as well as the lesser wing of the sphenoid. The middle cranial fossa contains the temporal lobes and includes the greater wing of the sphenoid, sella turcica, and most of the temporal bones. The posterior cranial fossa contains the occipital lobes, cerebellum, and medulla and includes the occipital bone.

      There are several foramina in the skull that allow for the passage of various structures. The most important foramina likely to appear in exams are listed below:

      – Foramen spinosum: located in the middle fossa and allows for the passage of the middle meningeal artery.
      – Foramen ovale: located in the middle fossa and allows for the passage of the mandibular division of the trigeminal nerve.
      – Foramen lacerum: located in the middle fossa and allows for the passage of the small meningeal branches of the ascending pharyngeal artery and emissary veins from the cavernous sinus.
      – Foramen magnum: located in the posterior fossa and allows for the passage of the spinal cord.
      – Jugular foramen: located in the posterior fossa and allows for the passage of cranial nerves IX, X, and XI.

      Understanding the location and function of these foramina is essential for medical professionals, as they play a crucial role in the diagnosis and treatment of various neurological conditions.

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  • Question 39 - What neurotransmitter is recognized for its significant role in triggering hunger? ...

    Incorrect

    • What neurotransmitter is recognized for its significant role in triggering hunger?

      Your Answer:

      Correct Answer: Orexin

      Explanation:

      Neurotransmitters and their functions:

      Orexin, which is derived from the Greek word for ‘appetite’, is responsible for regulating arousal, wakefulness, and appetite. It is also known as hypocretin and is produced in the hypothalamus. Orexin increases the craving for food.

      Glutamate is an excitatory amino acid that plays a crucial role in the nervous system. It is responsible for transmitting signals between nerve cells and is involved in learning and memory.

      Prolactin is a neurotransmitter produced by the hypothalamus. It is also known as ‘dopamine inhibitory factor’ and is important in the regulation of sexual function. Prolactin levels increase during pregnancy and breastfeeding.

      Serotonin is a monoamine neurotransmitter that has a range of actions, including decreasing appetite. It is involved in regulating mood, sleep, and appetite. Low levels of serotonin have been linked to depression and anxiety.

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  • Question 40 - Which pathway's dopamine blockade is responsible for the antipsychotic-induced extrapyramidal side effects? ...

    Incorrect

    • Which pathway's dopamine blockade is responsible for the antipsychotic-induced extrapyramidal side effects?

      Your Answer:

      Correct Answer: Nigrostriatal

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

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      • Neurosciences
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  • Question 41 - What is the condition that occurs when there is a loss of dopaminergic...

    Incorrect

    • What is the condition that occurs when there is a loss of dopaminergic cells in the substantia nigra?

      Your Answer:

      Correct Answer: Parkinson's disease

      Explanation:

      The Basal Ganglia: Functions and Disorders

      The basal ganglia are a group of subcortical structures that play a crucial role in controlling movement and some cognitive processes. The components of the basal ganglia include the striatum (caudate, putamen, nucleus accumbens), subthalamic nucleus, globus pallidus, and substantia nigra (divided into pars compacta and pars reticulata). The putamen and globus pallidus are collectively referred to as the lenticular nucleus.

      The basal ganglia are connected in a complex loop, with the cortex projecting to the striatum, the striatum to the internal segment of the globus pallidus, the internal segment of the globus pallidus to the thalamus, and the thalamus back to the cortex. This loop is responsible for regulating movement and cognitive processes.

      However, problems with the basal ganglia can lead to several conditions. Huntington’s chorea is caused by degeneration of the caudate nucleus, while Wilson’s disease is characterized by copper deposition in the basal ganglia. Parkinson’s disease is associated with degeneration of the substantia nigra, and hemiballism results from damage to the subthalamic nucleus.

      In summary, the basal ganglia are a crucial part of the brain that regulate movement and some cognitive processes. Disorders of the basal ganglia can lead to significant neurological conditions that affect movement and other functions.

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      • Neurosciences
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  • Question 42 - Which type of ion channel is activated by binding of a specific molecule...

    Incorrect

    • Which type of ion channel is activated by binding of a specific molecule (ligand)?

      Your Answer:

      Correct Answer: 5HT-3

      Explanation:

      All serotonin receptors, except for 5-HT3, are coupled with G proteins instead of being ligand gated ion channels.

      Serotonin (5-hydroxytryptamine, 5-HT) receptors are primarily G protein receptors, except for 5-HT3, which is a ligand-gated receptor. It is important to remember that 5-HT3 is most commonly associated with nausea. Additionally, 5-HT7 is linked to circadian rhythms. The stimulation of 5-HT2 receptors is believed to be responsible for the side effects of insomnia, agitation, and sexual dysfunction that are associated with the use of selective serotonin reuptake inhibitors (SSRIs).

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  • Question 43 - What EEG alterations are observed in individuals with Creutzfeldt-Jakob disease? ...

    Incorrect

    • What EEG alterations are observed in individuals with Creutzfeldt-Jakob disease?

      Your Answer:

      Correct Answer: Periodic sharp wave complexes

      Explanation:

      The typical EEG pattern for CJD includes periodic sharp wave complexes, which is a diagnostic criterion. Lewy body dementia may show generalized slow wave activity, but if it is more prominent in the temporal and parietal regions, it may indicate Alzheimer’s disease. Toxic encephalopathies, such as lithium toxicity, may show periodic triphasic waves on EEG. For more information, see Smith SJ’s article EEG in neurological conditions other than epilepsy: when does it help, what does it add? (2005).

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  • Question 44 - Which statement about the glossopharyngeal nerve is false? ...

    Incorrect

    • Which statement about the glossopharyngeal nerve is false?

      Your Answer:

      Correct Answer: Controls the muscles of mastication

      Explanation:

      The trigeminal nerve is responsible for controlling the muscles involved in chewing, while the glossopharyngeal nerves consist of both motor and sensory fibers that originate from nuclei in the medulla oblongata. The motor fibers of the glossopharyngeal nerves stimulate the pharyngeal muscles and parotid gland secretory cells, while the sensory fibers transmit impulses from the posterior third of the tongue, tonsils, and pharynx to the cerebral cortex.

      Overview of Cranial Nerves and Their Functions

      The cranial nerves are a complex system of nerves that originate from the brain and control various functions of the head and neck. There are twelve cranial nerves, each with a specific function and origin. The following table provides a simplified overview of the cranial nerves, including their origin, skull exit, modality, and functions.

      The first cranial nerve, the olfactory nerve, originates from the telencephalon and exits through the cribriform plate. It is a sensory nerve that controls the sense of smell. The second cranial nerve, the optic nerve, originates from the diencephalon and exits through the optic foramen. It is a sensory nerve that controls vision.

      The third cranial nerve, the oculomotor nerve, originates from the midbrain and exits through the superior orbital fissure. It is a motor nerve that controls eye movement, pupillary constriction, and lens accommodation. The fourth cranial nerve, the trochlear nerve, also originates from the midbrain and exits through the superior orbital fissure. It is a motor nerve that controls eye movement.

      The fifth cranial nerve, the trigeminal nerve, originates from the pons and exits through different foramina depending on the division. It is a mixed nerve that controls chewing and sensation of the anterior 2/3 of the scalp. It also tenses the tympanic membrane to dampen loud noises.

      The sixth cranial nerve, the abducens nerve, originates from the pons and exits through the superior orbital fissure. It is a motor nerve that controls eye movement. The seventh cranial nerve, the facial nerve, also originates from the pons and exits through the internal auditory canal. It is a mixed nerve that controls facial expression, taste of the anterior 2/3 of the tongue, and tension on the stapes to dampen loud noises.

      The eighth cranial nerve, the vestibulocochlear nerve, originates from the pons and exits through the internal auditory canal. It is a sensory nerve that controls hearing. The ninth cranial nerve, the glossopharyngeal nerve, originates from the medulla and exits through the jugular foramen. It is a mixed nerve that controls taste of the posterior 1/3 of the tongue, elevation of the larynx and pharynx, and swallowing.

      The tenth cranial nerve, the vagus nerve, also originates from the medulla and exits through the jugular foramen. It is a mixed nerve that controls swallowing, voice production, and parasympathetic supply to nearly all thoracic and abdominal viscera. The eleventh cranial nerve, the accessory nerve, originates from the medulla and exits through the jugular foramen. It is a motor nerve that controls shoulder shrugging and head turning.

      The twelfth cranial nerve, the hypoglossal nerve, originates from the medulla and exits through the hypoglossal canal. It is a motor nerve that controls tongue movement. Overall, the cranial nerves play a crucial role in controlling various functions of the head and neck, and any damage of dysfunction can have significant consequences.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 45 - What is a true statement about senile plaques? ...

    Incorrect

    • What is a true statement about senile plaques?

      Your Answer:

      Correct Answer: They consist of beta amyloid

      Explanation:

      Senile plaques are formed by beta amyloid proteins that have folded abnormally and are found in the extracellular space of the grey matter. While they are present in smaller quantities during normal aging, they are insoluble. These plaques are created due to the improper cleavage of Amyloid Precursor Protein (APP), a transmembrane protein whose function is not fully understood.

      Alzheimer’s disease is characterized by both macroscopic and microscopic changes in the brain. Macroscopic changes include cortical atrophy, ventricular dilation, and depigmentation of the locus coeruleus. Microscopic changes include the presence of senile plaques, neurofibrillary tangles, gliosis, degeneration of the nucleus of Meynert, and Hirano bodies. Senile plaques are extracellular deposits of beta amyloid in the gray matter of the brain, while neurofibrillary tangles are intracellular inclusion bodies that consist primarily of hyperphosphorylated tau. Gliosis is marked by increases in activated microglia and reactive astrocytes near the sites of amyloid plaques. The nucleus of Meynert degenerates in Alzheimer’s, resulting in a decrease in acetylcholine in the brain. Hirano bodies are actin-rich, eosinophilic intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure and are regarded as a nonspecific manifestation of neuronal degeneration. These changes in the brain contribute to the cognitive decline and memory loss seen in Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 46 - Which pathway is believed to be responsible for the development of negative symptoms...

    Incorrect

    • Which pathway is believed to be responsible for the development of negative symptoms in schizophrenia due to the blockage of D-2 receptors?

      Your Answer:

      Correct Answer: The mesocortical pathway

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 47 - Age-related plaques are made up of what substances? ...

    Incorrect

    • Age-related plaques are made up of what substances?

      Your Answer:

      Correct Answer: Beta amyloid

      Explanation:

      Alzheimer’s disease is characterized by both macroscopic and microscopic changes in the brain. Macroscopic changes include cortical atrophy, ventricular dilation, and depigmentation of the locus coeruleus. Microscopic changes include the presence of senile plaques, neurofibrillary tangles, gliosis, degeneration of the nucleus of Meynert, and Hirano bodies. Senile plaques are extracellular deposits of beta amyloid in the gray matter of the brain, while neurofibrillary tangles are intracellular inclusion bodies that consist primarily of hyperphosphorylated tau. Gliosis is marked by increases in activated microglia and reactive astrocytes near the sites of amyloid plaques. The nucleus of Meynert degenerates in Alzheimer’s, resulting in a decrease in acetylcholine in the brain. Hirano bodies are actin-rich, eosinophilic intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure and are regarded as a nonspecific manifestation of neuronal degeneration. These changes in the brain contribute to the cognitive decline and memory loss seen in Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 48 - What evidence indicates a diagnosis of dementia pugilistica? ...

    Incorrect

    • What evidence indicates a diagnosis of dementia pugilistica?

      Your Answer:

      Correct Answer: A history of recurrent head injury

      Explanation:

      Dementia Pugilistica: A Neurodegenerative Condition Resulting from Neurotrauma

      Dementia pugilistica, also known as chronic traumatic encephalopathy (CTE), is a neurodegenerative condition that results from neurotrauma. It is commonly seen in boxers and NFL players, but can also occur in anyone with neurotrauma. The condition is characterized by symptoms such as gait ataxia, slurred speech, impaired hearing, tremors, disequilibrium, neurobehavioral disturbances, and progressive cognitive decline.

      Most cases of dementia pugilistica present with early onset cognitive deficits, and behavioral signs exhibited by patients include aggression, suspiciousness, paranoia, childishness, hypersexuality, depression, and restlessness. The progression of the condition leads to more prominent behavioral symptoms such as difficulty with impulse control, irritability, inappropriateness, and explosive outbursts of aggression.

      Neuropathological abnormalities have been identified in CTE, with the most unique feature being the abnormal accumulation of tau in neurons and glia in an irregular, focal, perivascular distribution and at the depths of cortical sulci. Abnormalities of the septum pellucidum, such as cavum and fenestration, are also a common feature.

      While the condition has become increasingly rare due to the progressive improvement in sports safety, it is important to recognize the potential long-term consequences of repeated head injuries and take steps to prevent them.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 49 - What methods are used to generate estimates of white matter tracts? ...

    Incorrect

    • What methods are used to generate estimates of white matter tracts?

      Your Answer:

      Correct Answer: DTI

      Explanation:

      Neuroimaging techniques can be divided into structural and functional types, although this distinction is becoming less clear as new techniques emerge. Structural techniques include computed tomography (CT) and magnetic resonance imaging (MRI), which use x-rays and magnetic fields, respectively, to produce images of the brain’s structure. Functional techniques, on the other hand, measure brain activity by detecting changes in blood flow of oxygen consumption. These include functional MRI (fMRI), emission tomography (PET and SPECT), perfusion MRI (pMRI), and magnetic resonance spectroscopy (MRS). Some techniques, such as diffusion tensor imaging (DTI), combine both structural and functional information to provide a more complete picture of the brain’s anatomy and function. DTI, for example, uses MRI to estimate the paths that water takes as it diffuses through white matter, allowing researchers to visualize white matter tracts.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 50 - In what circumstances are neurofibrillary tangles less commonly observed? ...

    Incorrect

    • In what circumstances are neurofibrillary tangles less commonly observed?

      Your Answer:

      Correct Answer: Vascular dementia

      Explanation:

      Tauopathies exhibit tangles, but vascular dementia is not classified as one.

      Alzheimer’s disease is characterized by both macroscopic and microscopic changes in the brain. Macroscopic changes include cortical atrophy, ventricular dilation, and depigmentation of the locus coeruleus. Microscopic changes include the presence of senile plaques, neurofibrillary tangles, gliosis, degeneration of the nucleus of Meynert, and Hirano bodies. Senile plaques are extracellular deposits of beta amyloid in the gray matter of the brain, while neurofibrillary tangles are intracellular inclusion bodies that consist primarily of hyperphosphorylated tau. Gliosis is marked by increases in activated microglia and reactive astrocytes near the sites of amyloid plaques. The nucleus of Meynert degenerates in Alzheimer’s, resulting in a decrease in acetylcholine in the brain. Hirano bodies are actin-rich, eosinophilic intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure and are regarded as a nonspecific manifestation of neuronal degeneration. These changes in the brain contribute to the cognitive decline and memory loss seen in Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 51 - Where is serotonin primarily produced in the body? ...

    Incorrect

    • Where is serotonin primarily produced in the body?

      Your Answer:

      Correct Answer: Raphe nuclei

      Explanation:

      Serotonin: Synthesis and Breakdown

      Serotonin, also known as 5-Hydroxytryptamine (5-HT), is synthesized in the central nervous system (CNS) in the raphe nuclei located in the brainstem, as well as in the gastrointestinal (GI) tract in enterochromaffin cells. The amino acid L-tryptophan, obtained from the diet, is used to synthesize serotonin. L-tryptophan can cross the blood-brain barrier, but serotonin cannot.

      The transformation of L-tryptophan into serotonin involves two steps. First, hydroxylation to 5-hydroxytryptophan is catalyzed by tryptophan hydroxylase. Second, decarboxylation of 5-hydroxytryptophan to serotonin (5-hydroxytryptamine) is catalyzed by L-aromatic amino acid decarboxylase.

      Serotonin is taken up from the synapse by a monoamine transporter (SERT). Substances that block this transporter include MDMA, amphetamine, cocaine, TCAs, and SSRIs. Serotonin is broken down by monoamine oxidase (MAO) and then by aldehyde dehydrogenase to 5-Hydroxyindoleacetic acid (5-HIAA).

    • This question is part of the following fields:

      • Neurosciences
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  • Question 52 - What cell type plays a significant role in the formation of the blood-brain...

    Incorrect

    • What cell type plays a significant role in the formation of the blood-brain barrier?

      Your Answer:

      Correct Answer: Astrocyte

      Explanation:

      Glial Cells: The Support System of the Central Nervous System

      The central nervous system is composed of two basic cell types: neurons and glial cells. Glial cells, also known as support cells, play a crucial role in maintaining the health and function of neurons. There are several types of glial cells, including macroglia (astrocytes and oligodendrocytes), ependymal cells, and microglia.

      Astrocytes are the most abundant type of glial cell and have numerous functions, such as providing structural support, repairing nervous tissue, nourishing neurons, contributing to the blood-brain barrier, and regulating neurotransmission and blood flow. There are two main types of astrocytes: protoplasmic and fibrous.

      Oligodendrocytes are responsible for the formation of myelin sheaths, which insulate and protect axons, allowing for faster and more efficient transmission of nerve impulses.

      Ependymal cells line the ventricular system and are involved in the circulation of cerebrospinal fluid (CSF) and fluid homeostasis in the brain. Specialized ependymal cells called choroid plexus cells produce CSF.

      Microglia are the immune cells of the CNS and play a crucial role in protecting the brain from infection and injury. They also contribute to the maintenance of neuronal health and function.

      In summary, glial cells are essential for the proper functioning of the central nervous system. They provide structural support, nourishment, insulation, and immune defense to neurons, ensuring the health and well-being of the brain and spinal cord.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 53 - From which region of the developing brain does the retina originate? ...

    Incorrect

    • From which region of the developing brain does the retina originate?

      Your Answer:

      Correct Answer: Diencephalon

      Explanation:

      The retina and optic nerves originate from protrusions of the diencephalon known as eye vesicles during development.

      Neurodevelopment: Understanding Brain Development

      The development of the central nervous system begins with the neuroectoderm, a specialized region of ectoderm. The embryonic brain is divided into three areas: the forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon). The prosencephalon further divides into the telencephalon and diencephalon, while the hindbrain subdivides into the metencephalon and myelencephalon.

      The telencephalon, of cerebrum, consists of the cerebral cortex, underlying white matter, and the basal ganglia. The diencephalon includes the prethalamus, thalamus, hypothalamus, subthalamus, epithalamus, and pretectum. The mesencephalon comprises the tectum, tegmentum, ventricular mesocoelia, cerebral peduncles, and several nuclei and fasciculi.

      The rhombencephalon includes the medulla, pons, and cerebellum, which can be subdivided into a variable number of transversal swellings called rhombomeres. In humans, eight rhombomeres can be distinguished, from caudal to rostral: Rh7-Rh1 and the isthmus. Rhombomeres Rh7-Rh4 form the myelencephalon, while Rh3-Rh1 form the metencephalon.

      Understanding neurodevelopment is crucial in comprehending brain development and its complexities. By studying the different areas of the embryonic brain, we can gain insight into the formation of the central nervous system and its functions.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 54 - An older woman presents to the emergency department with sudden onset of left...

    Incorrect

    • An older woman presents to the emergency department with sudden onset of left leg dysfunction, urinary incontinence, and abulia. As her time in the department progresses, her left arm also becomes affected. She has a history of vascular disease. Which artery do you suspect is involved?

      Your Answer:

      Correct Answer: Anterior cerebral artery

      Explanation:

      When there is a blockage in the anterior cerebral artery, the legs are typically impacted more than the arms. Additionally, a common symptom is abulia, which is a lack of determination of difficulty making firm decisions.

      Brain Blood Supply and Consequences of Occlusion

      The brain receives blood supply from the internal carotid and vertebral arteries, which form the circle of Willis. The circle of Willis acts as a shunt system in case of vessel damage. The three main vessels arising from the circle are the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA). Occlusion of these vessels can result in various neurological deficits. ACA occlusion may cause hemiparesis of the contralateral foot and leg, sensory loss, and frontal signs. MCA occlusion is the most common and can lead to hemiparesis, dysphasia/aphasia, neglect, and visual field defects. PCA occlusion may cause alexia, loss of sensation, hemianopia, prosopagnosia, and cranial nerve defects. It is important to recognize these consequences to provide appropriate treatment.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 55 - Which neuroimaging technique that maps cortical activation uses the non-invasive BOLD method? ...

    Incorrect

    • Which neuroimaging technique that maps cortical activation uses the non-invasive BOLD method?

      Your Answer:

      Correct Answer: Functional MRI (fMRI)

      Explanation:

      The BOLD technique is used by fMRI to non-invasively map cortical activation, while PET and SPECT require the administration of a radioactive isotope and are invasive. Although all three magnetic imaging techniques are non-invasive, fMRI stands out for its use of the BOLD technique.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 56 - What is the neurotransmitter that prevents the pituitary gland from releasing prolactin? ...

    Incorrect

    • What is the neurotransmitter that prevents the pituitary gland from releasing prolactin?

      Your Answer:

      Correct Answer: Dopamine

      Explanation:

      Hormones and their functions:

      Dopamine, also known as prolactin inhibitory factor, is released from the hypothalamus. Antipsychotics, which are dopamine antagonists, are often linked to increased prolactin levels.

      Oxytocin, released from the posterior pituitary, plays a crucial role in sexual reproduction.

      Substance P is present throughout the brain and is essential in pain perception.

      Vasopressin, a peptide hormone, is released from the posterior pituitary.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 57 - What is true about the pathology of Alzheimer's disease? ...

    Incorrect

    • What is true about the pathology of Alzheimer's disease?

      Your Answer:

      Correct Answer: Enlargement of the inferior horn of the lateral ventricle is seen

      Explanation:

      Normal ageing can exhibit both neurofibrillary tangles and senile plaques, while Alzheimer’s disease typically shows atrophy in the frontal, parietal, and medial temporal lobes.

      Alzheimer’s disease is characterized by both macroscopic and microscopic changes in the brain. Macroscopic changes include cortical atrophy, ventricular dilation, and depigmentation of the locus coeruleus. Microscopic changes include the presence of senile plaques, neurofibrillary tangles, gliosis, degeneration of the nucleus of Meynert, and Hirano bodies. Senile plaques are extracellular deposits of beta amyloid in the gray matter of the brain, while neurofibrillary tangles are intracellular inclusion bodies that consist primarily of hyperphosphorylated tau. Gliosis is marked by increases in activated microglia and reactive astrocytes near the sites of amyloid plaques. The nucleus of Meynert degenerates in Alzheimer’s, resulting in a decrease in acetylcholine in the brain. Hirano bodies are actin-rich, eosinophilic intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure and are regarded as a nonspecific manifestation of neuronal degeneration. These changes in the brain contribute to the cognitive decline and memory loss seen in Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 58 - Which medical conditions have been linked to the potential involvement of nitric oxide...

    Incorrect

    • Which medical conditions have been linked to the potential involvement of nitric oxide in their development?

      Your Answer:

      Correct Answer: Depression

      Explanation:

      Nitric Oxide and Depression

      Recent research has indicated that nitric oxide (NO) may play a role in the development of depression. Inhibitors of NO synthase have been found to exhibit antidepressant-like effects in preclinical studies, suggesting that NO may be involved in the pathogenesis of depression. These findings suggest that targeting NO signaling pathways may be a potential therapeutic approach for treating depression. Further research is needed to fully understand the role of NO in depression and to develop effective treatments based on this knowledge.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 59 - What is the role of the Golgi apparatus in a neuron? ...

    Incorrect

    • What is the role of the Golgi apparatus in a neuron?

      Your Answer:

      Correct Answer: Packaging of macromolecules

      Explanation:

      Melanin

      Melanin is a pigment found in various parts of the body, including the skin, hair, and eyes. It is produced by specialized cells called melanocytes, which are located in the skin’s basal layer. The function of melanin in the body is not fully understood, but it is thought to play a role in protecting the skin from the harmful effects of ultraviolet (UV) radiation from the sun. Additionally, melanin may be a by-product of neurotransmitter synthesis, although this function is not well established. Overall, the role of melanin in the body is an area of ongoing research.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 60 - Which condition is linked to tardive dyskinesia? ...

    Incorrect

    • Which condition is linked to tardive dyskinesia?

      Your Answer:

      Correct Answer: Hyperkinetic dysarthria

      Explanation:

      Dysarthria is a speech disorder that affects the volume, rate, tone, of quality of spoken language. There are different types of dysarthria, each with its own set of features, associated conditions, and localisation. The types of dysarthria include spastic, flaccid, hypokinetic, hyperkinetic, and ataxic.

      Spastic dysarthria is characterised by explosive and forceful speech at a slow rate and is associated with conditions such as pseudobulbar palsy and spastic hemiplegia.

      Flaccid dysarthria, on the other hand, is characterised by a breathy, nasal voice and imprecise consonants and is associated with conditions such as myasthenia gravis.

      Hypokinetic dysarthria is characterised by slow, quiet speech with a tremor and is associated with conditions such as Parkinson’s disease.

      Hyperkinetic dysarthria is characterised by a variable rate, inappropriate stoppages, and a strained quality and is associated with conditions such as Huntington’s disease, Sydenham’s chorea, and tardive dyskinesia.

      Finally, ataxic dysarthria is characterised by rapid, monopitched, and slurred speech and is associated with conditions such as Friedreich’s ataxia and alcohol abuse. The localisation of each type of dysarthria varies, with spastic and flaccid dysarthria affecting the upper and lower motor neurons, respectively, and hypokinetic, hyperkinetic, and ataxic dysarthria affecting the extrapyramidal and cerebellar regions of the brain.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 61 - What is another name for the forebrain in the developing embryo? ...

    Incorrect

    • What is another name for the forebrain in the developing embryo?

      Your Answer:

      Correct Answer: Prosencephalon

      Explanation:

      Neurodevelopment: Understanding Brain Development

      The development of the central nervous system begins with the neuroectoderm, a specialized region of ectoderm. The embryonic brain is divided into three areas: the forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon). The prosencephalon further divides into the telencephalon and diencephalon, while the hindbrain subdivides into the metencephalon and myelencephalon.

      The telencephalon, of cerebrum, consists of the cerebral cortex, underlying white matter, and the basal ganglia. The diencephalon includes the prethalamus, thalamus, hypothalamus, subthalamus, epithalamus, and pretectum. The mesencephalon comprises the tectum, tegmentum, ventricular mesocoelia, cerebral peduncles, and several nuclei and fasciculi.

      The rhombencephalon includes the medulla, pons, and cerebellum, which can be subdivided into a variable number of transversal swellings called rhombomeres. In humans, eight rhombomeres can be distinguished, from caudal to rostral: Rh7-Rh1 and the isthmus. Rhombomeres Rh7-Rh4 form the myelencephalon, while Rh3-Rh1 form the metencephalon.

      Understanding neurodevelopment is crucial in comprehending brain development and its complexities. By studying the different areas of the embryonic brain, we can gain insight into the formation of the central nervous system and its functions.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 62 - Which statement accurately describes the role of the basal ganglia? ...

    Incorrect

    • Which statement accurately describes the role of the basal ganglia?

      Your Answer:

      Correct Answer: Degeneration of the basal ganglia is associated with movement problems

      Explanation:

      The Basal Ganglia: Functions and Disorders

      The basal ganglia are a group of subcortical structures that play a crucial role in controlling movement and some cognitive processes. The components of the basal ganglia include the striatum (caudate, putamen, nucleus accumbens), subthalamic nucleus, globus pallidus, and substantia nigra (divided into pars compacta and pars reticulata). The putamen and globus pallidus are collectively referred to as the lenticular nucleus.

      The basal ganglia are connected in a complex loop, with the cortex projecting to the striatum, the striatum to the internal segment of the globus pallidus, the internal segment of the globus pallidus to the thalamus, and the thalamus back to the cortex. This loop is responsible for regulating movement and cognitive processes.

      However, problems with the basal ganglia can lead to several conditions. Huntington’s chorea is caused by degeneration of the caudate nucleus, while Wilson’s disease is characterized by copper deposition in the basal ganglia. Parkinson’s disease is associated with degeneration of the substantia nigra, and hemiballism results from damage to the subthalamic nucleus.

      In summary, the basal ganglia are a crucial part of the brain that regulate movement and some cognitive processes. Disorders of the basal ganglia can lead to significant neurological conditions that affect movement and other functions.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 63 - Which feature is not very useful in distinguishing between Parkinson's disease and progressive...

    Incorrect

    • Which feature is not very useful in distinguishing between Parkinson's disease and progressive supranuclear palsy?

      Your Answer:

      Correct Answer: Pallor of the substantia nigra

      Explanation:

      Both conditions exhibit pallor of the substantia nigra. However, in PSP, the locus coeruleus is typically unaffected, whereas in Parkinson’s disease, it shows pallor. Therefore, if there is pallor in this area, it would indicate Parkinson’s disease.

      Pathology of Progressive Supranuclear Palsy

      Progressive supranuclear palsy is a rare disorder that affects gait and balance, often accompanied by changes in mood, behavior, and dementia. The macroscopic changes observed in this condition include pallor of the substantia nigra (with sparing of the locus coeruleus), mild midbrain atrophy, atrophy of the superior cerebellar peduncles, and discolouration of the dentate nucleus. On a microscopic level, gliosis and the presence of neurofibrillary tangles and tau inclusions in both astrocytes and oligodendrocytes (coiled bodies) are observed, particularly in the substantia nigra, subthalamic nucleus, and globus pallidus.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 64 - What does the presence of a fenestrated cavum septum pellucidum indicate? ...

    Incorrect

    • What does the presence of a fenestrated cavum septum pellucidum indicate?

      Your Answer:

      Correct Answer: Punch drunk syndrome

      Explanation:

      A fenestrated cavum septum pellucidum is linked to dementia pugilistica.

      Dementia Pugilistica: A Neurodegenerative Condition Resulting from Neurotrauma

      Dementia pugilistica, also known as chronic traumatic encephalopathy (CTE), is a neurodegenerative condition that results from neurotrauma. It is commonly seen in boxers and NFL players, but can also occur in anyone with neurotrauma. The condition is characterized by symptoms such as gait ataxia, slurred speech, impaired hearing, tremors, disequilibrium, neurobehavioral disturbances, and progressive cognitive decline.

      Most cases of dementia pugilistica present with early onset cognitive deficits, and behavioral signs exhibited by patients include aggression, suspiciousness, paranoia, childishness, hypersexuality, depression, and restlessness. The progression of the condition leads to more prominent behavioral symptoms such as difficulty with impulse control, irritability, inappropriateness, and explosive outbursts of aggression.

      Neuropathological abnormalities have been identified in CTE, with the most unique feature being the abnormal accumulation of tau in neurons and glia in an irregular, focal, perivascular distribution and at the depths of cortical sulci. Abnormalities of the septum pellucidum, such as cavum and fenestration, are also a common feature.

      While the condition has become increasingly rare due to the progressive improvement in sports safety, it is important to recognize the potential long-term consequences of repeated head injuries and take steps to prevent them.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 65 - What is a true statement about Lewy bodies? ...

    Incorrect

    • What is a true statement about Lewy bodies?

      Your Answer:

      Correct Answer: Cortical Lewy bodies typically lack a halo on staining

      Explanation:

      The absence of a halo distinguishes the Lewy bodies found in the brainstem from those found in the cortex. These bodies consist of alpha-synuclein protein, along with other proteins like ubiquitin, neurofilament protein, and alpha B crystallin. Additionally, they may contain tau proteins and are sometimes encircled by neurofibrillary tangles.

      Lewy body dementia is a neurodegenerative disorder that is characterized by both macroscopic and microscopic changes in the brain. Macroscopically, there is cerebral atrophy, but it is less marked than in Alzheimer’s disease, and the brain weight is usually in the normal range. There is also pallor of the substantia nigra and the locus coeruleus, which are regions of the brain that produce dopamine and norepinephrine, respectively.

      Microscopically, Lewy body dementia is characterized by the presence of intracellular protein accumulations called Lewy bodies. The major component of a Lewy body is alpha synuclein, and as they grow, they start to draw in other proteins such as ubiquitin. Lewy bodies are also found in Alzheimer’s disease, but they tend to be in the amygdala. They can also be found in healthy individuals, although it has been suggested that these may be pre-clinical cases of dementia with Lewy bodies. Lewy bodies are also found in other neurodegenerative disorders such as progressive supranuclear palsy, corticobasal degeneration, and multiple system atrophy.

      In Lewy body dementia, Lewy bodies are mainly found within the brainstem, but they are also found in non-brainstem regions such as the amygdaloid nucleus, parahippocampal gyrus, cingulate cortex, and cerebral neocortex. Classic brainstem Lewy bodies are spherical intraneuronal cytoplasmic inclusions, characterized by hyaline eosinophilic cores, concentric lamellar bands, narrow pale halos, and immunoreactivity for alpha synuclein and ubiquitin. In contrast, cortical Lewy bodies typically lack a halo.

      Most brains with Lewy body dementia also show some plaques and tangles, although in most instances, the lesions are not nearly as severe as in Alzheimer’s disease. Neuronal loss and gliosis are usually restricted to brainstem regions, particularly the substantia nigra and locus ceruleus.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 66 - Which of the following is an example of a non-fluent aphasia? ...

    Incorrect

    • Which of the following is an example of a non-fluent aphasia?

      Your Answer:

      Correct Answer: Broca's aphasia

      Explanation:

      Aphasia is a language impairment that affects the production of comprehension of speech, as well as the ability to read of write. The areas involved in language are situated around the Sylvian fissure, referred to as the ‘perisylvian language area’. For repetition, the primary auditory cortex, Wernicke, Broca via the Arcuate fasciculus (AF), Broca recodes into articulatory plan, primary motor cortex, and pyramidal system to cranial nerves are involved. For oral reading, the visual cortex to Wernicke and the same processes as for repetition follows. For writing, Wernicke via AF to premotor cortex for arm and hand, movement planned, sent to motor cortex. The classification of aphasia is complex and imprecise, with the Boston Group classification and Luria’s aphasia interpretation being the most influential. The important subtypes of aphasia include global aphasia, Broca’s aphasia, Wernicke’s aphasia, conduction aphasia, anomic aphasia, transcortical motor aphasia, and transcortical sensory aphasia. Additional syndromes include alexia without agraphia, alexia with agraphia, and pure word deafness.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 67 - What is the primary component of Hirano bodies? ...

    Incorrect

    • What is the primary component of Hirano bodies?

      Your Answer:

      Correct Answer: Actin

      Explanation:

      Actin is the primary component of Hirano bodies, which are indicative of neurodegeneration but lack specificity.

      Alzheimer’s disease is characterized by both macroscopic and microscopic changes in the brain. Macroscopic changes include cortical atrophy, ventricular dilation, and depigmentation of the locus coeruleus. Microscopic changes include the presence of senile plaques, neurofibrillary tangles, gliosis, degeneration of the nucleus of Meynert, and Hirano bodies. Senile plaques are extracellular deposits of beta amyloid in the gray matter of the brain, while neurofibrillary tangles are intracellular inclusion bodies that consist primarily of hyperphosphorylated tau. Gliosis is marked by increases in activated microglia and reactive astrocytes near the sites of amyloid plaques. The nucleus of Meynert degenerates in Alzheimer’s, resulting in a decrease in acetylcholine in the brain. Hirano bodies are actin-rich, eosinophilic intracytoplasmic inclusions which have a highly characteristic crystalloid fine structure and are regarded as a nonspecific manifestation of neuronal degeneration. These changes in the brain contribute to the cognitive decline and memory loss seen in Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 68 - Which of the following is a catecholamine? ...

    Incorrect

    • Which of the following is a catecholamine?

      Your Answer:

      Correct Answer: Adrenaline

      Explanation:

      Catecholamines are a group of chemical compounds that have a distinct structure consisting of a benzene ring with two hydroxyl groups, an intermediate ethyl chain, and a terminal amine group. These compounds play an important role in the body and are involved in various physiological processes. The three main catecholamines found in the body are dopamine, adrenaline, and noradrenaline. All of these compounds are derived from the amino acid tyrosine. Overall, catecholamines are essential for maintaining proper bodily functions and are involved in a wide range of physiological processes.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 69 - What is the main structural component of alpha-synuclein? ...

    Incorrect

    • What is the main structural component of alpha-synuclein?

      Your Answer:

      Correct Answer: Lewy bodies

      Explanation:

      Parkinson’s Disease Pathology

      Parkinson’s disease is a neurodegenerative disorder that affects the central nervous system. The pathology of Parkinson’s disease is very similar to that of Lewy body dementia. The macroscopic features of Parkinson’s disease include pallor of the substantia nigra (midbrain) and locus coeruleus (pons). The microscopic changes include the presence of Lewy bodies, which are intracellular aggregates of alpha-synuclein. Additionally, there is a loss of dopaminergic cells from the substantia nigra pars compacta. These changes contribute to the motor symptoms of Parkinson’s disease, such as tremors, rigidity, and bradykinesia. Understanding the pathology of Parkinson’s disease is crucial for developing effective treatments and improving the quality of life for those affected by this condition.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 70 - What is a true statement about the neocortex? ...

    Incorrect

    • What is a true statement about the neocortex?

      Your Answer:

      Correct Answer: It contains both pyramidal and nonpyramidal cells

      Explanation:

      The Cerebral Cortex and Neocortex

      The cerebral cortex is the outermost layer of the cerebral hemispheres and is composed of three parts: the archicortex, paleocortex, and neocortex. The neocortex accounts for 90% of the cortex and is involved in higher functions such as thought and language. It is divided into 6-7 layers, with two main cell types: pyramidal cells and nonpyramidal cells. The surface of the neocortex is divided into separate areas, each given a number by Brodmann (e.g. Brodmann’s area 17 is the primary visual cortex). The surface is folded to increase surface area, with grooves called sulci and ridges called gyri. The neocortex is responsible for higher cognitive functions and is essential for human consciousness.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 71 - What is the term used to describe the small, horizontally arranged folds resembling...

    Incorrect

    • What is the term used to describe the small, horizontally arranged folds resembling pleats on the outer surface of the cerebellum?

      Your Answer:

      Correct Answer: Folia

      Explanation:

      Brain Anatomy

      The brain is a complex organ with various regions responsible for different functions. The major areas of the cerebrum (telencephalon) include the frontal lobe, parietal lobe, occipital lobe, temporal lobe, insula, corpus callosum, fornix, anterior commissure, and striatum. The cerebrum is responsible for complex learning, language acquisition, visual and auditory processing, memory, and emotion processing.

      The diencephalon includes the thalamus, hypothalamus and pituitary, pineal gland, and mammillary body. The thalamus is a major relay point and processing center for all sensory impulses (excluding olfaction). The hypothalamus and pituitary are involved in homeostasis and hormone release. The pineal gland secretes melatonin to regulate circadian rhythms. The mammillary body is a relay point involved in memory.

      The cerebellum is primarily concerned with movement and has two major hemispheres with an outer cortex made up of gray matter and an inner region of white matter. The cerebellum provides precise timing and appropriate patterns of skeletal muscle contraction for smooth, coordinated movements and agility needed for daily life.

      The brainstem includes the substantia nigra, which is involved in controlling and regulating activities of the motor and premotor cortical areas for smooth voluntary movements, eye movement, reward seeking, the pleasurable effects of substance misuse, and learning.

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      • Neurosciences
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  • Question 72 - A child is referred to a neurologist. On entering the neurologist's room, the...

    Incorrect

    • A child is referred to a neurologist. On entering the neurologist's room, the child is observed to have a broad-based gait. When introduced, the child's speech is noted to be abnormal. When the child attempts to shake the doctor's hand, a tremor is observed. Which area of the brain is likely to be dysfunctional?

      Your Answer:

      Correct Answer: Cerebellum

      Explanation:

      Cerebellar Dysfunction: Symptoms and Signs

      Cerebellar dysfunction is a condition that affects the cerebellum, a part of the brain responsible for coordinating movement and balance. The symptoms and signs of cerebellar dysfunction include ataxia, intention tremor, nystagmus, broad-based gait, slurred speech, dysdiadochokinesis, and dysmetria (lack of finger-nose coordination).

      Ataxia refers to the lack of coordination of voluntary movements, resulting in unsteady gait, difficulty with balance, and clumsiness. Intention tremor is a type of tremor that occurs during voluntary movements, such as reaching for an object. Nystagmus is an involuntary movement of the eyes, characterized by rapid, jerky movements.

      Broad-based gait refers to a wide stance while walking, which is often seen in individuals with cerebellar dysfunction. Slurred speech, also known as dysarthria, is a common symptom of cerebellar dysfunction, which affects the ability to articulate words clearly. Dysdiadochokinesis is the inability to perform rapid alternating movements, such as tapping the fingers on the palm of the hand.

      Dysmetria refers to the inability to accurately judge the distance and direction of movements, resulting in errors in reaching for objects of touching the nose with the finger. These symptoms and signs of cerebellar dysfunction can be caused by a variety of conditions, including stroke, multiple sclerosis, and alcoholism. Treatment depends on the underlying cause and may include medications, physical therapy, and surgery.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 73 - Can you identify the neurotransmitter that is often studied and also referred to...

    Incorrect

    • Can you identify the neurotransmitter that is often studied and also referred to as prolactin-inhibiting factor (PIF)?

      Your Answer:

      Correct Answer: Dopamine

      Explanation:

      Prolactin secretion from the anterior pituitary gland is inhibited by dopamine, which is also referred to as prolactin-inhibiting factor (PIF) and prolactin-inhibiting hormone (PIH). The reason why antipsychotic medications are linked to hyperprolactinaemia is due to the antagonism of dopamine receptors. On the other hand, serotonin and melatonin seem to stimulate prolactin secretion. While animal studies have indicated that adrenaline and noradrenaline can decrease prolactin secretion, their effect is not as significant as that of dopamine.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 74 - What is a true statement about microglia? ...

    Incorrect

    • What is a true statement about microglia?

      Your Answer:

      Correct Answer: It is mesodermal in origin

      Explanation:

      Glial Cells: The Support System of the Central Nervous System

      The central nervous system is composed of two basic cell types: neurons and glial cells. Glial cells, also known as support cells, play a crucial role in maintaining the health and function of neurons. There are several types of glial cells, including macroglia (astrocytes and oligodendrocytes), ependymal cells, and microglia.

      Astrocytes are the most abundant type of glial cell and have numerous functions, such as providing structural support, repairing nervous tissue, nourishing neurons, contributing to the blood-brain barrier, and regulating neurotransmission and blood flow. There are two main types of astrocytes: protoplasmic and fibrous.

      Oligodendrocytes are responsible for the formation of myelin sheaths, which insulate and protect axons, allowing for faster and more efficient transmission of nerve impulses.

      Ependymal cells line the ventricular system and are involved in the circulation of cerebrospinal fluid (CSF) and fluid homeostasis in the brain. Specialized ependymal cells called choroid plexus cells produce CSF.

      Microglia are the immune cells of the CNS and play a crucial role in protecting the brain from infection and injury. They also contribute to the maintenance of neuronal health and function.

      In summary, glial cells are essential for the proper functioning of the central nervous system. They provide structural support, nourishment, insulation, and immune defense to neurons, ensuring the health and well-being of the brain and spinal cord.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 75 - What statement accurately describes ionotropic receptors? ...

    Incorrect

    • What statement accurately describes ionotropic receptors?

      Your Answer:

      Correct Answer: GABA-A is an example of an ionotropic receptor

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 76 - Which condition is commonly linked to pronator drift? ...

    Incorrect

    • Which condition is commonly linked to pronator drift?

      Your Answer:

      Correct Answer: Spasticity

      Explanation:

      Spasticity is the correct answer as pronator drift is a sign of upper motor neuron lesions, while the other options are indicative of lower motor neuron lesions.

      Understanding Pronator Drift in Neurological Examinations

      Pronator drift is a neurological sign that is commonly observed during a medical examination. This sign is elicited by asking the patient to flex their arms forward at a 90-degree angle to the shoulders, supinate their forearms, close their eyes, and maintain the position. In a normal scenario, the position should remain unchanged. However, in some cases, one arm may be seen to pronate.

      Pronator drift is typically caused by an upper motor neuron lesion. There are various underlying conditions that can lead to this type of lesion, including stroke, multiple sclerosis, and brain tumors. The presence of pronator drift can help healthcare professionals to identify the location and severity of the lesion, as well as to determine the appropriate course of treatment.

      Overall, understanding pronator drift is an important aspect of neurological examinations. By recognizing this sign and its underlying causes, healthcare professionals can provide more accurate diagnoses and develop effective treatment plans for their patients.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 77 - What is a true statement about GABA? ...

    Incorrect

    • What is a true statement about GABA?

      Your Answer:

      Correct Answer: Flumazenil is a GABA-A antagonist

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 78 - What is the term used to describe an intense and brief emotional reaction...

    Incorrect

    • What is the term used to describe an intense and brief emotional reaction to a minor trigger?

      Your Answer:

      Correct Answer: Emotional lability

      Explanation:

      Multiple Sclerosis: An Overview

      Multiple sclerosis is a neurological disorder that is classified into three categories: primary progressive, relapsing-remitting, and secondary progressive. Primary progressive multiple sclerosis affects 5-10% of patients and is characterized by a steady progression with no remissions. Relapsing-remitting multiple sclerosis affects 20-30% of patients and presents with a relapsing-remitting course but does not lead to serious disability. Secondary progressive multiple sclerosis affects 60% of patients and initially presents with a relapsing-remitting course but is then followed by a phase of progressive deterioration.

      The disorder typically begins between the ages of 20 and 40 and is characterized by multiple demyelinating lesions that have a preference for the optic nerves, cerebellum, brainstem, and spinal cord. Patients with multiple sclerosis present with a variety of neurological signs that reflect the presence and distribution of plaques. Ocular features of multiple sclerosis include optic neuritis, internuclear ophthalmoplegia, and ocular motor cranial neuropathy.

      Multiple sclerosis is more common in women than in men and is seen with increasing frequency as the distance from the equator increases. It is believed to be caused by a combination of genetic and environmental factors, with monozygotic concordance at 25%. Overall, multiple sclerosis is a predominantly white matter disease that can have a significant impact on a patient’s quality of life.

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      • Neurosciences
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  • Question 79 - The pineal gland secretes which of the following? ...

    Incorrect

    • The pineal gland secretes which of the following?

      Your Answer:

      Correct Answer: Melatonin

      Explanation:

      Melatonin: The Hormone of Darkness

      Melatonin is a hormone that is produced in the pineal gland from serotonin. This hormone is known to be released in higher amounts during the night, especially in dark environments. Melatonin plays a crucial role in regulating the sleep-wake cycle and is often referred to as the hormone of darkness.

      The production of melatonin is influenced by the amount of light that enters the eyes. When it is dark, the pineal gland releases more melatonin, which helps to promote sleep. On the other hand, when it is light, the production of melatonin is suppressed, which helps to keep us awake and alert.

      Melatonin is also known to have antioxidant properties and may help to protect the body against oxidative stress. It has been suggested that melatonin may have a role in the prevention of certain diseases, such as cancer and neurodegenerative disorders.

      Overall, melatonin is an important hormone that plays a crucial role in regulating our sleep-wake cycle and may have other health benefits as well.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 80 - What does the following describe: A clinical manifestation that quickly appears and indicates...

    Incorrect

    • What does the following describe: A clinical manifestation that quickly appears and indicates a localized disruption in brain function, believed to be caused by a vascular issue and lasting for more than 24 hours.

      Your Answer:

      Correct Answer: Stroke

      Explanation:

      Cerebrovascular accidents (CVA), also known as strokes, are defined by the World Health Organization as a sudden onset of focal neurological symptoms lasting more than 24 hours and presumed to be of vascular origin. Strokes can be caused by either infarction of hemorrhage, with infarction being more common. Hemorrhagic strokes tend to be more severe. Intracranial hemorrhage can be primary, caused mainly by hypertension, of subarachnoid, caused by the rupture of an aneurysm of angioma. Primary intracranial hemorrhage is most common in individuals aged 60-80 and often occurs during exertion. Infarction can be caused by thrombosis of embolism, with thrombosis being more common. Atherosclerosis, often caused by hypertension, is the main cause of infarction. CT scanning is the preferred diagnostic tool during the first 48 hours after a stroke as it can distinguish between infarcts and hemorrhages. Recovery from embolism is generally quicker and more complete than from thrombosis due to the availability of collateral channels.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 81 - Which sensory component is correctly matched with its corresponding cranial nerve reflex? ...

    Incorrect

    • Which sensory component is correctly matched with its corresponding cranial nerve reflex?

      Your Answer:

      Correct Answer: Gag reflex - IX cranial nerve

      Explanation:

      The question specifically requests the sensory aspect.

      Cranial Nerve Reflexes

      When it comes to questions on cranial nerve reflexes, it is important to match the reflex to the nerves involved. Here are some examples:

      – Pupillary light reflex: involves the optic nerve (sensory) and oculomotor nerve (motor).
      – Accommodation reflex: involves the optic nerve (sensory) and oculomotor nerve (motor).
      – Jaw jerk: involves the trigeminal nerve (sensory and motor).
      – Corneal reflex: involves the trigeminal nerve (sensory) and facial nerve (motor).
      – Vestibulo-ocular reflex: involves the vestibulocochlear nerve (sensory) and oculomotor, trochlear, and abducent nerves (motor).

      Another example of a cranial nerve reflex is the gag reflex, which involves the glossopharyngeal nerve (sensory) and the vagus nerve (motor). This reflex is important for protecting the airway from foreign objects of substances that may trigger a gag reflex. It is also used as a diagnostic tool to assess the function of these nerves.

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      • Neurosciences
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  • Question 82 - I'm sorry, as an AI language model, I cannot provide an answer without...

    Incorrect

    • I'm sorry, as an AI language model, I cannot provide an answer without additional context. Please provide more information of clarify your question.

      Your Answer:

      Correct Answer: Wernicke's aphasia

      Explanation:

      Aphasia is a language impairment that affects the production of comprehension of speech, as well as the ability to read of write. The areas involved in language are situated around the Sylvian fissure, referred to as the ‘perisylvian language area’. For repetition, the primary auditory cortex, Wernicke, Broca via the Arcuate fasciculus (AF), Broca recodes into articulatory plan, primary motor cortex, and pyramidal system to cranial nerves are involved. For oral reading, the visual cortex to Wernicke and the same processes as for repetition follows. For writing, Wernicke via AF to premotor cortex for arm and hand, movement planned, sent to motor cortex. The classification of aphasia is complex and imprecise, with the Boston Group classification and Luria’s aphasia interpretation being the most influential. The important subtypes of aphasia include global aphasia, Broca’s aphasia, Wernicke’s aphasia, conduction aphasia, anomic aphasia, transcortical motor aphasia, and transcortical sensory aphasia. Additional syndromes include alexia without agraphia, alexia with agraphia, and pure word deafness.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 83 - During which stage of sleep do sleep spindles appear on an EEG in...

    Incorrect

    • During which stage of sleep do sleep spindles appear on an EEG in a typical individual?

      Your Answer:

      Correct Answer: Stage 2

      Explanation:

      Sleep is a complex process that involves different stages. These stages are categorized into Non-REM (NREM) and Rapid Eye Movement (REM) sleep. Each cycle of NREM and REM sleep takes around 90 to 110 minutes.

      Stage 1 is the lightest stage of sleep, where the sleeper may experience sudden muscle contractions and a sense of falling. The brain waves during this stage are called theta waves.

      In Stage 2, eye movement stops, and brain waves become lower. Sleep spindles and K complexes, which are rapid bursts of 12-14 Hz waves, are seen during this stage.

      Stages 3 and 4 are referred to as deep sleep of delta sleep. There is no eye movement of muscle activity during these stages. Children may experience night terrors of somnambulism during these stages.

      REM sleep is characterized by rapid, shallow breathing and rapid, jerky eye movements. Most dreaming occurs during REM sleep.

      Overall, the different stages of sleep are important for the body to rest and rejuvenate. Understanding these stages can help individuals improve their sleep quality and overall health.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 84 - Which of the following do not describe the features of REM sleep? ...

    Incorrect

    • Which of the following do not describe the features of REM sleep?

      Your Answer:

      Correct Answer: K complexes on the EEG

      Explanation:

      During REM sleep, the EEG patterns resemble those observed during wakefulness, characterized by numerous beta-rhythms that are fast.

      Sleep Stages

      Sleep is divided into two distinct states called rapid eye movement (REM) and non-rapid eye movement (NREM). NREM is subdivided into four stages.

      Sleep stage
      Approx % of time spent in stage
      EEG findings
      Comment

      I
      5%
      Theta waves (4-7 Hz)
      The dozing off stage. Characterized by hypnic jerks: spontaneous myoclonic contractions associated with a sensation of twitching of falling.

      II
      45%
      Theta waves, K complexes and sleep spindles (short bursts of 12-14 Hz activity)
      Body enters a more subdued state including a drop in temperature, relaxed muscles, and slowed breathing and heart rate. At the same time, brain waves show a new pattern and eye movement stops.

      III
      15%
      Delta waves (0-4 Hz)
      Deepest stage of sleep (high waking threshold). The length of stage 3 decreases over the course of the night.

      IV
      15%
      Mixed, predominantly beta
      High dream activity.

      The percentage of REM sleep decreases with age.

      It takes the average person 15-20 minutes to fall asleep, this is called sleep latency (characterised by the onset of stage I sleep). Once asleep one descends through stages I-II and then III-IV (deep stages). After about 90 minutes of sleep one enters REM. The rest of the sleep comprises of cycles through the stages. As the sleep progresses the periods of REM become greater and the periods of NREM become less. During an average night’s sleep one spends 25% of the sleep in REM and 75% in NREM.

      REM sleep has certain characteristics that separate it from NREM

      Characteristics of REM sleep

      – Autonomic instability (variability in heart rate, respiratory rate, and BP)
      – Loss of muscle tone
      – Dreaming
      – Rapid eye movements
      – Penile erection

      Deafness:

      (No information provided on deafness in relation to sleep stages)

    • This question is part of the following fields:

      • Neurosciences
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  • Question 85 - The histopathological findings from a post-mortem of an older man with long standing...

    Incorrect

    • The histopathological findings from a post-mortem of an older man with long standing memory difficulties reveals neuronal and glial tau aggregation in addition to pronounced atrophy of the frontal and temporal lobes.

      What is the most probable diagnosis for an elderly man with these histopathological findings?

      Your Answer:

      Correct Answer: Pick's disease

      Explanation:

      Alzheimer’s disease is not characterized by significant frontal lobe atrophy, but rather by early medial temporal lobe atrophy (MTA) on MRI, particularly in the hippocampus, entorhinal cortex, amygdala, and parahippocampus. In contrast, frontotemporal lobar degeneration (FTLD) typically affects the frontal and anterior temporal lobes in behavioral variant frontotemporal dementia (bvFTD of Pick’s disease), the left anterior temporal lobe in semantic dementia (SD), and the left perisylvian fissure in progressive nonfluent aphasia (PNFA).

      Frontotemporal Lobar Degeneration (FTLD) is a pathological term that refers to a group of neurodegenerative disorders that affect the frontal and temporal lobes of the brain. FTLD is classified into several subtypes based on the main protein component of neuronal and glial abnormal inclusions and their distribution. The three main proteins associated with FTLD are Tau, TDP-43, and FUS. Each FTD clinical phenotype has been associated with different proportions of these proteins. Macroscopic changes in FTLD include atrophy of the frontal and temporal lobes, with focal gyral atrophy that resembles knives. Microscopic changes in FTLD-Tau include neuronal and glial tau aggregation, with further sub-classification based on the existence of different isoforms of tau protein. FTLD-TDP is characterized by cytoplasmic inclusions of TDP-43 in neurons, while FTLD-FUS is characterized by cytoplasmic inclusions of FUS.

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      • Neurosciences
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  • Question 86 - Which area of the cerebellum is responsible for regulating precise and delicate movements...

    Incorrect

    • Which area of the cerebellum is responsible for regulating precise and delicate movements of the body?

      Your Answer:

      Correct Answer: Spinocerebellum

      Explanation:

      The Cerebellum: Anatomy and Function

      The cerebellum is a part of the brain that consists of two hemispheres and a median vermis. It is separated from the cerebral hemispheres by the tentorium cerebelli and connected to the brain stem by the cerebellar peduncles. Anatomically, it is divided into three lobes: the flocculonodular lobe, anterior lobe, and posterior lobe. Functionally, it is divided into three regions: the vestibulocerebellum, spinocerebellum, and cerebrocerebellum.

      The vestibulocerebellum, located in the flocculonodular lobe, is responsible for balance and spatial orientation. The spinocerebellum, located in the medial section of the anterior and posterior lobes, is involved in fine-tuned body movements. The cerebrocerebellum, located in the lateral section of the anterior and posterior lobes, is involved in planning movement and the conscious assessment of movement.

      Overall, the cerebellum plays a crucial role in motor coordination and control. Its different regions and lobes work together to ensure smooth and precise movements of the body.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 87 - Which process breaks down dopamine? ...

    Incorrect

    • Which process breaks down dopamine?

      Your Answer:

      Correct Answer: Monoamine oxidase

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 88 - What is the most consistently observed pathology in schizophrenia? ...

    Incorrect

    • What is the most consistently observed pathology in schizophrenia?

      Your Answer:

      Correct Answer: Reduced total grey matter volume

      Explanation:

      Alzheimer’s disease is associated with the presence of Hirano bodies.

      Schizophrenia is a pathology that is characterized by a number of structural and functional brain alterations. Structural alterations include enlargement of the ventricles, reductions in total brain and gray matter volume, and regional reductions in the amygdala, parahippocampal gyrus, and temporal lobes. Antipsychotic treatment may be associated with gray matter loss over time, and even drug-naïve patients show volume reductions. Cerebral asymmetry is also reduced in affected individuals and healthy relatives. Functional alterations include diminished activation of frontal regions during cognitive tasks and increased activation of temporal regions during hallucinations. These findings suggest that schizophrenia is associated with both macroscopic and functional changes in the brain.

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      • Neurosciences
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  • Question 89 - From which amino acids are the catecholamines derived? ...

    Incorrect

    • From which amino acids are the catecholamines derived?

      Your Answer:

      Correct Answer: Tyrosine

      Explanation:

      Catecholamines are a group of chemical compounds that have a distinct structure consisting of a benzene ring with two hydroxyl groups, an intermediate ethyl chain, and a terminal amine group. These compounds play an important role in the body and are involved in various physiological processes. The three main catecholamines found in the body are dopamine, adrenaline, and noradrenaline. All of these compounds are derived from the amino acid tyrosine. Overall, catecholamines are essential for maintaining proper bodily functions and are involved in a wide range of physiological processes.

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      • Neurosciences
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  • Question 90 - What is a correct statement about the pathology of Lewy body dementia? ...

    Incorrect

    • What is a correct statement about the pathology of Lewy body dementia?

      Your Answer:

      Correct Answer: There is a loss of dopaminergic neurons

      Explanation:

      Lewy body dementia is a neurodegenerative disorder that is characterized by both macroscopic and microscopic changes in the brain. Macroscopically, there is cerebral atrophy, but it is less marked than in Alzheimer’s disease, and the brain weight is usually in the normal range. There is also pallor of the substantia nigra and the locus coeruleus, which are regions of the brain that produce dopamine and norepinephrine, respectively.

      Microscopically, Lewy body dementia is characterized by the presence of intracellular protein accumulations called Lewy bodies. The major component of a Lewy body is alpha synuclein, and as they grow, they start to draw in other proteins such as ubiquitin. Lewy bodies are also found in Alzheimer’s disease, but they tend to be in the amygdala. They can also be found in healthy individuals, although it has been suggested that these may be pre-clinical cases of dementia with Lewy bodies. Lewy bodies are also found in other neurodegenerative disorders such as progressive supranuclear palsy, corticobasal degeneration, and multiple system atrophy.

      In Lewy body dementia, Lewy bodies are mainly found within the brainstem, but they are also found in non-brainstem regions such as the amygdaloid nucleus, parahippocampal gyrus, cingulate cortex, and cerebral neocortex. Classic brainstem Lewy bodies are spherical intraneuronal cytoplasmic inclusions, characterized by hyaline eosinophilic cores, concentric lamellar bands, narrow pale halos, and immunoreactivity for alpha synuclein and ubiquitin. In contrast, cortical Lewy bodies typically lack a halo.

      Most brains with Lewy body dementia also show some plaques and tangles, although in most instances, the lesions are not nearly as severe as in Alzheimer’s disease. Neuronal loss and gliosis are usually restricted to brainstem regions, particularly the substantia nigra and locus ceruleus.

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      • Neurosciences
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  • Question 91 - What can be said about alterations in dopamine transporter levels observed in individuals...

    Incorrect

    • What can be said about alterations in dopamine transporter levels observed in individuals with ADHD?

      Your Answer:

      Correct Answer: Elevated due to psychostimulant treatment

      Explanation:

      The density of striatal dopamine transporters in individuals with ADHD is influenced by their prior exposure to psychostimulants. ADHD is a complex disorder that involves dysfunction in multiple neurotransmitter systems, including dopamine, adrenergic, cholinergic, and serotonergic systems. Dopamine systems have received significant attention due to their role in regulating psychomotor activity, motivation, inhibition, and attention. Psychostimulants increase dopamine availability by blocking striatal dopamine transporters. Individuals with untreated ADHD have lower levels of dopamine transporters, while those who have received psychostimulants have higher levels.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 92 - What is the neurotransmitter that encourages sleep? ...

    Incorrect

    • What is the neurotransmitter that encourages sleep?

      Your Answer:

      Correct Answer: Acetylcholine

      Explanation:

      REM sleep is facilitated by the presence of acetylcholine (Ach), while dopamine, histamine, noradrenaline, and serotonin act as inhibitors of sleep.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 93 - What is a true statement about histamine? ...

    Incorrect

    • What is a true statement about histamine?

      Your Answer:

      Correct Answer: It is metabolised by histamine methyltransferase

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 94 - Which type of channel opening in the plasma membrane leads to the depolarization...

    Incorrect

    • Which type of channel opening in the plasma membrane leads to the depolarization of a neuron?

      Your Answer:

      Correct Answer: Na

      Explanation:

      Understanding Action Potentials in Neurons and Muscle Cells

      The membrane potential is a crucial aspect of cell physiology, and it exists across the plasma membrane of most cells. However, in neurons and muscle cells, this membrane potential can change over time. When a cell is not stimulated, it is in a resting state, and the inside of the cell is negatively charged compared to the outside. This resting membrane potential is typically around -70mV, and it is maintained by the Na/K pump, which maintains a high concentration of Na outside and K inside the cell.

      To trigger an action potential, the membrane potential must be raised to around -55mV. This can occur when a neurotransmitter binds to the postsynaptic neuron and opens some ion channels. Once the membrane potential reaches -55mV, a cascade of events is initiated, leading to the opening of a large number of Na channels and causing the cell to depolarize. As the membrane potential reaches around +40 mV, the Na channels close, and the K gates open, allowing K to flood out of the cell and causing the membrane potential to fall back down. This process is irreversible and is critical for the transmission of signals in neurons and the contraction of muscle cells.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 95 - What is the term used to describe the condition where a person cannot...

    Incorrect

    • What is the term used to describe the condition where a person cannot identify faces?

      Your Answer:

      Correct Answer: Prosopagnosia

      Explanation:

      Agnosia is a condition where a person loses the ability to recognize objects, persons, sounds, shapes, of smells, despite having no significant memory loss of defective senses. There are different types of agnosia, such as prosopagnosia (inability to recognize familiar faces), anosognosia (inability to recognize one’s own condition/illness), autotopagnosia (inability to orient parts of the body), phonagnosia (inability to recognize familiar voices), simultanagnosia (inability to appreciate two objects in the visual field at the same time), and astereoagnosia (inability to recognize objects by touch).

    • This question is part of the following fields:

      • Neurosciences
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  • Question 96 - What type of MRI scan is available? ...

    Incorrect

    • What type of MRI scan is available?

      Your Answer:

      Correct Answer: DTI

      Explanation:

      Neuroimaging techniques can be divided into structural and functional types, although this distinction is becoming less clear as new techniques emerge. Structural techniques include computed tomography (CT) and magnetic resonance imaging (MRI), which use x-rays and magnetic fields, respectively, to produce images of the brain’s structure. Functional techniques, on the other hand, measure brain activity by detecting changes in blood flow of oxygen consumption. These include functional MRI (fMRI), emission tomography (PET and SPECT), perfusion MRI (pMRI), and magnetic resonance spectroscopy (MRS). Some techniques, such as diffusion tensor imaging (DTI), combine both structural and functional information to provide a more complete picture of the brain’s anatomy and function. DTI, for example, uses MRI to estimate the paths that water takes as it diffuses through white matter, allowing researchers to visualize white matter tracts.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 97 - What is a true statement about the cerebellum? ...

    Incorrect

    • What is a true statement about the cerebellum?

      Your Answer:

      Correct Answer: The vestibulocerebellum controls balance and spatial orientation

      Explanation:

      The Cerebellum: Anatomy and Function

      The cerebellum is a part of the brain that consists of two hemispheres and a median vermis. It is separated from the cerebral hemispheres by the tentorium cerebelli and connected to the brain stem by the cerebellar peduncles. Anatomically, it is divided into three lobes: the flocculonodular lobe, anterior lobe, and posterior lobe. Functionally, it is divided into three regions: the vestibulocerebellum, spinocerebellum, and cerebrocerebellum.

      The vestibulocerebellum, located in the flocculonodular lobe, is responsible for balance and spatial orientation. The spinocerebellum, located in the medial section of the anterior and posterior lobes, is involved in fine-tuned body movements. The cerebrocerebellum, located in the lateral section of the anterior and posterior lobes, is involved in planning movement and the conscious assessment of movement.

      Overall, the cerebellum plays a crucial role in motor coordination and control. Its different regions and lobes work together to ensure smooth and precise movements of the body.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 98 - What is the entity that carries out phagocytosis in the central nervous system?...

    Incorrect

    • What is the entity that carries out phagocytosis in the central nervous system?

      Your Answer:

      Correct Answer: Microglia

      Explanation:

      Glial Cells: The Support System of the Central Nervous System

      The central nervous system is composed of two basic cell types: neurons and glial cells. Glial cells, also known as support cells, play a crucial role in maintaining the health and function of neurons. There are several types of glial cells, including macroglia (astrocytes and oligodendrocytes), ependymal cells, and microglia.

      Astrocytes are the most abundant type of glial cell and have numerous functions, such as providing structural support, repairing nervous tissue, nourishing neurons, contributing to the blood-brain barrier, and regulating neurotransmission and blood flow. There are two main types of astrocytes: protoplasmic and fibrous.

      Oligodendrocytes are responsible for the formation of myelin sheaths, which insulate and protect axons, allowing for faster and more efficient transmission of nerve impulses.

      Ependymal cells line the ventricular system and are involved in the circulation of cerebrospinal fluid (CSF) and fluid homeostasis in the brain. Specialized ependymal cells called choroid plexus cells produce CSF.

      Microglia are the immune cells of the CNS and play a crucial role in protecting the brain from infection and injury. They also contribute to the maintenance of neuronal health and function.

      In summary, glial cells are essential for the proper functioning of the central nervous system. They provide structural support, nourishment, insulation, and immune defense to neurons, ensuring the health and well-being of the brain and spinal cord.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 99 - Which substance has the highest level of permeability through the blood brain barrier?...

    Incorrect

    • Which substance has the highest level of permeability through the blood brain barrier?

      Your Answer:

      Correct Answer: Lipid soluble molecules

      Explanation:

      Understanding the Blood Brain Barrier

      The blood brain barrier (BBB) is a crucial component of the brain’s defense system against harmful chemicals and ion imbalances. It is a semi-permeable membrane formed by tight junctions of endothelial cells in the brain’s capillaries, which separates the blood from the cerebrospinal fluid. However, certain areas of the BBB, known as circumventricular organs, are fenestrated to allow neurosecretory products to enter the blood.

      When it comes to MRCPsych questions, the focus is on the following aspects of the BBB: the tight junctions between endothelial cells, the ease with which lipid-soluble molecules pass through compared to water-soluble ones, the difficulty large and highly charged molecules face in passing through, the increased permeability of the BBB during inflammation, and the theoretical ability of nasally administered drugs to bypass the BBB.

      It is important to remember the specific circumventricular organs where the BBB is fenestrated, including the posterior pituitary and the area postrema. Understanding the BBB’s function and characteristics is essential for medical professionals to diagnose and treat neurological disorders effectively.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 100 - What is a correct statement about the blood brain barrier? ...

    Incorrect

    • What is a correct statement about the blood brain barrier?

      Your Answer:

      Correct Answer: Nasally administered drugs can bypass the blood brain barrier

      Explanation:

      Understanding the Blood Brain Barrier

      The blood brain barrier (BBB) is a crucial component of the brain’s defense system against harmful chemicals and ion imbalances. It is a semi-permeable membrane formed by tight junctions of endothelial cells in the brain’s capillaries, which separates the blood from the cerebrospinal fluid. However, certain areas of the BBB, known as circumventricular organs, are fenestrated to allow neurosecretory products to enter the blood.

      When it comes to MRCPsych questions, the focus is on the following aspects of the BBB: the tight junctions between endothelial cells, the ease with which lipid-soluble molecules pass through compared to water-soluble ones, the difficulty large and highly charged molecules face in passing through, the increased permeability of the BBB during inflammation, and the theoretical ability of nasally administered drugs to bypass the BBB.

      It is important to remember the specific circumventricular organs where the BBB is fenestrated, including the posterior pituitary and the area postrema. Understanding the BBB’s function and characteristics is essential for medical professionals to diagnose and treat neurological disorders effectively.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 101 - What signs of symptoms might indicate the presence of Balint's syndrome? ...

    Incorrect

    • What signs of symptoms might indicate the presence of Balint's syndrome?

      Your Answer:

      Correct Answer: Simultanagnosia

      Explanation:

      Parietal Lobe Dysfunction: Types and Symptoms

      The parietal lobe is a part of the brain that plays a crucial role in processing sensory information and integrating it with other cognitive functions. Dysfunction in this area can lead to various symptoms, depending on the location and extent of the damage.

      Dominant parietal lobe dysfunction, often caused by a stroke, can result in Gerstmann’s syndrome, which includes finger agnosia, dyscalculia, dysgraphia, and right-left disorientation. Non-dominant parietal lobe dysfunction, on the other hand, can cause anosognosia, dressing apraxia, spatial neglect, and constructional apraxia.

      Bilateral damage to the parieto-occipital lobes, a rare condition, can lead to Balint’s syndrome, which is characterized by oculomotor apraxia, optic ataxia, and simultanagnosia. These symptoms can affect a person’s ability to shift gaze, interact with objects, and perceive multiple objects at once.

      In summary, parietal lobe dysfunction can manifest in various ways, and understanding the specific symptoms can help diagnose and treat the underlying condition.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 102 - From which amino acid is norepinephrine synthesized? ...

    Incorrect

    • From which amino acid is norepinephrine synthesized?

      Your Answer:

      Correct Answer: Tyrosine

      Explanation:

      Norepinephrine: Synthesis, Release, and Breakdown

      Norepinephrine is synthesized from tyrosine through a series of enzymatic reactions. The first step involves the conversion of tyrosine to L-DOPA by tyrosine hydroxylase. L-DOPA is then converted to dopamine by DOPA decarboxylase. Dopamine is further converted to norepinephrine by dopamine beta-hydroxylase. Finally, norepinephrine is converted to epinephrine by phenylethanolamine-N-methyltransferase.

      The primary site of norepinephrine release is the locus coeruleus, also known as the blue spot, which is located in the pons. Once released, norepinephrine is broken down by two enzymes: catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). These enzymes play a crucial role in regulating the levels of norepinephrine in the body.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 103 - Which of the following eosinophilic inclusion bodies are observed as a neuropathological discovery...

    Incorrect

    • Which of the following eosinophilic inclusion bodies are observed as a neuropathological discovery in individuals with Alzheimer's disease?

      Your Answer:

      Correct Answer: Hirano bodies

      Explanation:

      Hirano bodies, Pick bodies, Lewy bodies, Negri bodies, and Barr bodies are all types of inclusion bodies that can be seen in various cells. Hirano bodies are rod-shaped structures found in the cytoplasm of neurons, composed of actin and other proteins. They are commonly seen in the hippocampus, along with granulovacuolar degeneration, which may represent lysosomal accumulations within neuronal cytoplasm. The clinical significance of these microscopic features is not yet fully understood. Pick bodies are masses of cytoskeletal elements seen in Pick’s disease, while Lewy bodies are abnormal protein aggregates that develop in nerve cells in Lewy body disease. Negri bodies are inclusion bodies seen in rabies, and Barr bodies are inactive X chromosomes in a female somatic cell.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 104 - Which statement about 5-Hydroxyindoleacetic acid (5-HIAA) is accurate? ...

    Incorrect

    • Which statement about 5-Hydroxyindoleacetic acid (5-HIAA) is accurate?

      Your Answer:

      Correct Answer: Low CSF levels are found in people with depression

      Explanation:

      Depression, suicidality, and aggression have been linked to low levels of 5-HIAA in the CSF.

      The Significance of 5-HIAA in Depression and Aggression

      During the 1980s, there was a brief period of interest in 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite. Studies found that up to a third of people with depression had low concentrations of 5-HIAA in their cerebrospinal fluid (CSF), while very few normal controls did. This suggests that 5-HIAA may play a role in depression.

      Furthermore, individuals with low CSF levels of 5-HIAA have been found to respond less effectively to antidepressants and are more likely to commit suicide. This finding has been replicated in multiple studies, indicating the significance of 5-HIAA in depression.

      Low levels of 5-HIAA are also associated with increased levels of aggression. This suggests that 5-HIAA may play a role in regulating aggressive behavior. Overall, the research on 5-HIAA highlights its potential importance in understanding and treating depression and aggression.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 105 - What is located within Brodmann area 22? ...

    Incorrect

    • What is located within Brodmann area 22?

      Your Answer:

      Correct Answer: Wernicke's area

      Explanation:

      Broca’s and Wernicke’s are two types of expressive dysphasia, which is characterized by difficulty producing speech despite intact comprehension. Dysarthria is a type of expressive dysphasia caused by damage to the speech production apparatus, while Broca’s aphasia is caused by damage to the area of the brain responsible for speech production, specifically Broca’s area located in Brodmann areas 44 and 45. On the other hand, Wernicke’s aphasia is a type of receptive of fluent aphasia caused by damage to the comprehension of speech, while the actual production of speech remains normal. Wernicke’s area is located in the posterior part of the superior temporal gyrus in the dominant hemisphere, within Brodmann area 22.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 106 - What is the primary neurotransmitter in the brain that has an inhibitory effect?...

    Incorrect

    • What is the primary neurotransmitter in the brain that has an inhibitory effect?

      Your Answer:

      Correct Answer: GABA

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 107 - What condition is most commonly associated with slow (<2.5 Hz) generalized spike-and-wave discharges...

    Incorrect

    • What condition is most commonly associated with slow (<2.5 Hz) generalized spike-and-wave discharges on the EEG?

      Your Answer:

      Correct Answer: Atypical absence seizures

      Explanation:

      Electroencephalography

      Electroencephalography (EEG) is a clinical test that records the brain’s spontaneous electrical activity over a short period of time using multiple electrodes placed on the scalp. It is mainly used to rule out organic conditions and can help differentiate dementia from other disorders such as metabolic encephalopathies, CJD, herpes encephalitis, and non-convulsive status epilepticus. EEG can also distinguish possible psychotic episodes and acute confusional states from non-convulsive status epilepticus.

      Not all abnormal EEGs represent an underlying condition, and psychotropic medications can affect EEG findings. EEG abnormalities can also be triggered purposely by activation procedures such as hyperventilation, photic stimulation, certain drugs, and sleep deprivation.

      Specific waveforms are seen in an EEG, including delta, theta, alpha, sigma, beta, and gamma waves. Delta waves are found frontally in adults and posteriorly in children during slow wave sleep, and excessive amounts when awake may indicate pathology. Theta waves are generally seen in young children, drowsy and sleeping adults, and during meditation. Alpha waves are seen posteriorly when relaxed and when the eyes are closed, and are also seen in meditation. Sigma waves are bursts of oscillatory activity that occur in stage 2 sleep. Beta waves are seen frontally when busy of concentrating, and gamma waves are seen in advanced/very experienced meditators.

      Certain conditions are associated with specific EEG changes, such as nonspecific slowing in early CJD, low voltage EEG in Huntington’s, diffuse slowing in encephalopathy, and reduced alpha and beta with increased delta and theta in Alzheimer’s.

      Common epileptiform patterns include spikes, spike/sharp waves, and spike-waves. Medications can have important effects on EEG findings, with clozapine decreasing alpha and increasing delta and theta, lithium increasing all waveforms, lamotrigine decreasing all waveforms, and valproate having inconclusive effects on delta and theta and increasing beta.

      Overall, EEG is a useful tool in clinical contexts for ruling out organic conditions and differentiating between various disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 108 - What is a true statement about Anton-Babinski syndrome? ...

    Incorrect

    • What is a true statement about Anton-Babinski syndrome?

      Your Answer:

      Correct Answer: Confabulation is a characteristic feature

      Explanation:

      Anton’s syndrome, also known as Anton-Babinski syndrome, is a condition that results from damage to the occipital lobe. People with this syndrome are cortically blind, but they are not aware of it and deny having any problem, a condition known as anosognosia. They may start falling over furniture as they cannot see, but they believe they can still see and describe their surroundings in detail, even though their descriptions are incorrect (confabulation). This syndrome is characterized by a lack of awareness of visual impairment, which can lead to significant difficulties in daily life.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 109 - Your consultant calls you into his room to show you an interesting case....

    Incorrect

    • Your consultant calls you into his room to show you an interesting case. When you enter you see a middle-aged female sat in a chair. The consultant places a hairbrush next to her which she immediately picks up and starts brushing her hair with. Which of the following terms best describes this observation?:

      Your Answer:

      Correct Answer: Utilization behaviour

      Explanation:

      Abnormal Motor Behaviours Associated with Utilization Behaviour

      Utilization behaviour (UB) is a condition where patients exhibit exaggerated and inappropriate motor responses to environmental cues and objects. This behaviour is automatic and instrumentally correct, but not contextually appropriate. For instance, a patient may start brushing their teeth when presented with a toothbrush, even in a setting where it is not expected. UB is caused by frontal lobe lesions that result in a loss of inhibitory control.

      Other motor abnormalities associated with UB include imitation behaviour, where patients tend to imitate the examiner’s behaviour, and the alien hand sign, where patients experience bizarre hand movements that they cannot control. Manual groping behaviour is also observed, where patients automatically manipulate objects placed in front of them. The grasp reflex, which is normal in infants, should not be present in children and adults. It is an automatic tendency to grip objects of stimuli, such as the examiner’s hand.

      Environmental Dependency Syndrome is another condition associated with UB. It describes deficits in personal control of action and an overreliance on social and physical environmental stimuli to guide behaviour in a social context. For example, a patient may start commenting on pictures in an examiner’s office, believing it to be an art gallery.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 110 - Which prion disease exhibits minimal of no spongiform alteration? ...

    Incorrect

    • Which prion disease exhibits minimal of no spongiform alteration?

      Your Answer:

      Correct Answer: Fatal familial insomnia (FFI)

      Explanation:

      Fatal familial insomnia (FFI) is characterized by minimal spongiform change, but notable thalamic atrophy and astrogliosis. Diagnosis of FFI relies heavily on immunohistochemistry and genotyping. In contrast, spongiform change is a hallmark of CJD and Kuru. The majority of CJD cases (85%) are sporadic, while only a small percentage are caused by consuming contaminated food (variant CJD of vCJD).

    • This question is part of the following fields:

      • Neurosciences
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  • Question 111 - Which of the options below does not belong to the category of small...

    Incorrect

    • Which of the options below does not belong to the category of small molecule neurotransmitters?

      Your Answer:

      Correct Answer: Prolactin

      Explanation:

      Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 112 - What is the most probable outcome of damage to Broca's area? ...

    Incorrect

    • What is the most probable outcome of damage to Broca's area?

      Your Answer:

      Correct Answer: Non-fluent aphasia

      Explanation:

      Broca’s and Wernicke’s are two types of expressive dysphasia, which is characterized by difficulty producing speech despite intact comprehension. Dysarthria is a type of expressive dysphasia caused by damage to the speech production apparatus, while Broca’s aphasia is caused by damage to the area of the brain responsible for speech production, specifically Broca’s area located in Brodmann areas 44 and 45. On the other hand, Wernicke’s aphasia is a type of receptive of fluent aphasia caused by damage to the comprehension of speech, while the actual production of speech remains normal. Wernicke’s area is located in the posterior part of the superior temporal gyrus in the dominant hemisphere, within Brodmann area 22.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 113 - A 62-year-old woman is referred to your clinic.
    Her daughter has noticed a progressive...

    Incorrect

    • A 62-year-old woman is referred to your clinic.
      Her daughter has noticed a progressive behavioural change in her mother. She is more aggressive whilst demanding attention. She giggles uncontrollably for no apparent reason, and has been seen wandering outside their house without proper clothing. She has also become more forgetful over the last six months.
      She is physically well and has no problems with her heart, blood pressure of diabetes. She is on no medication. You conduct cognitive testing and refer the woman for an EEG.
      What is the most probable EEG finding?

      Your Answer:

      Correct Answer: Normal EEG

      Explanation:

      The individual’s age, behavioral changes, disinhibition, and fatuous giggling suggest a diagnosis of frontal lobe dementia, which is further supported by their physical examination. The absence of focal abnormalities on EEG rules out the possibility of vascular dementia. Typically, EEG results are normal during the early stages of this condition and remain so until the advanced stages.

    • This question is part of the following fields:

      • Neurosciences
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  • Question 114 - In a h