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  • Question 1 - What is believed to be the cause of the negative symptoms observed in...

    Correct

    • What is believed to be the cause of the negative symptoms observed in individuals with schizophrenia?

      Your Answer: Decreased dopaminergic activity in the frontal lobe

      Explanation:

      Psychosis is associated with heightened dopaminergic activity in the striatum, while negative symptoms are linked to reduced dopaminergic activity in the frontal lobe.

      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
      15.7
      Seconds
  • Question 2 - The substance that boosts hunger and is produced by the hypothalamus is: ...

    Correct

    • The substance that boosts hunger and is produced by the hypothalamus is:

      Your Answer: Neuropeptide Y

      Explanation:

      Appetite Control Hormones

      The regulation of appetite is influenced by various hormones in the body. Neuropeptide Y, which is produced by the hypothalamus, stimulates appetite. On the other hand, leptin, which is produced by adipose tissue, suppresses appetite. Ghrelin, which is mainly produced by the gut, increases appetite. Cholecystokinin (CCK), which is also produced by the gut, reduces appetite. These hormones play a crucial role in maintaining a healthy balance of food intake and energy expenditure.

    • This question is part of the following fields:

      • Neurosciences
      14.3
      Seconds
  • Question 3 - A 50-year-old individual has experienced a stroke resulting in aphasia, hemiplegia, and sensory...

    Correct

    • A 50-year-old individual has experienced a stroke resulting in aphasia, hemiplegia, and sensory impairment. What is the most probable area of the brain that has been affected?

      Your Answer: Dominant middle cerebral artery

      Explanation:

      The middle cerebral artery is the most frequent location for cerebral infarction, resulting in contralateral paralysis and sensory loss. If the dominant hemisphere is affected, language impairment such as Broca’s of Wernicke’s aphasia may occur. Bilateral anterior cerebellar artery blockage is uncommon but can lead to akinetic mutism, which is characterized by a loss of speech and movement. Non-dominant middle cerebral artery blockage can cause contralateral neglect, as well as motor and sensory dysfunction, but language is typically unaffected. The occlusion of the posterior inferior cerebellar artery can result in lateral medullary syndrome, also known as Wallenberg syndrome, which is characterized by crossed contralateral and trunk sensory deficits and ipsilateral sensory deficits affecting the face and cranial nerves. Emboli in the ophthalmic artery can cause temporary vision loss, also known as amaurosis fugax, which is more commonly caused by emboli originating in the carotid artery.

    • This question is part of the following fields:

      • Neurosciences
      18.1
      Seconds
  • Question 4 - What is the hypothalamic nucleus that is responsible for regulating heat generation and...

    Correct

    • What is the hypothalamic nucleus that is responsible for regulating heat generation and conservation?

      Your Answer: Posterior

      Explanation:

      Functions of the Hypothalamus

      The hypothalamus is a vital part of the brain that plays a crucial role in regulating various bodily functions. It receives and integrates sensory information about the internal environment and directs actions to control internal homeostasis. The hypothalamus contains several nuclei and fiber tracts, each with specific functions.

      The suprachiasmatic nucleus (SCN) is responsible for regulating circadian rhythms. Neurons in the SCN have an intrinsic rhythm of discharge activity and receive input from the retina. The SCN is considered the body’s master clock, but it has multiple connections with other hypothalamic nuclei.

      Body temperature control is mainly under the control of the preoptic, anterior, and posterior nuclei, which have temperature-sensitive neurons. As the temperature goes above 37ºC, warm-sensitive neurons are activated, triggering parasympathetic activity to promote heat loss. As the temperature goes below 37ºC, cold-sensitive neurons are activated, triggering sympathetic activity to promote conservation of heat.

      The hypothalamus also plays a role in regulating prolactin secretion. Dopamine is tonically secreted by dopaminergic neurons that project from the arcuate nucleus of the hypothalamus into the anterior pituitary gland via the tuberoinfundibular pathway. The dopamine that is released acts on lactotrophic cells through D2-receptors, inhibiting prolactin synthesis. In the absence of pregnancy of lactation, prolactin is constitutively inhibited by dopamine. Dopamine antagonists result in hyperprolactinemia, while dopamine agonists inhibit prolactin secretion.

      In summary, the hypothalamus is a complex structure that regulates various bodily functions, including circadian rhythms, body temperature, and prolactin secretion. Dysfunction of the hypothalamus can lead to various disorders, such as sleep-rhythm disorder, diabetes insipidus, hyperprolactinemia, and obesity.

    • This question is part of the following fields:

      • Neurosciences
      16.7
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  • Question 5 - Which statement accurately describes the role of the basal ganglia? ...

    Correct

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

      Your 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
      22.7
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  • Question 6 - What structure is situated in the anterior part of the brain? ...

    Correct

    • What structure is situated in the anterior part of the brain?

      Your Answer: Nucleus accumbens

      Explanation:

      The nucleus accumbens is situated in the forebrain and is a component of the basal ganglia, which is one of the three major divisions of the brain. The remaining choices refer to structures located in the midbrain.

      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
      13.6
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  • Question 7 - In which part of the skull is the structure located in the posterior...

    Correct

    • In which part of the skull is the structure located in the posterior cranial fossa?

      Your Answer: Foramen magnum

      Explanation:

      The base of the skull contains a sizable opening called the foramen magnum, which permits the spinal cord to pass through.

      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.

    • This question is part of the following fields:

      • Neurosciences
      7.8
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  • Question 8 - Which hypothalamic nucleus plays the most significant role in establishing the set point...

    Correct

    • Which hypothalamic nucleus plays the most significant role in establishing the set point for daily circadian rhythms?

      Your Answer: Suprachiasmatic

      Explanation:

      Functions of the Hypothalamus

      The hypothalamus is a vital part of the brain that plays a crucial role in regulating various bodily functions. It receives and integrates sensory information about the internal environment and directs actions to control internal homeostasis. The hypothalamus contains several nuclei and fiber tracts, each with specific functions.

      The suprachiasmatic nucleus (SCN) is responsible for regulating circadian rhythms. Neurons in the SCN have an intrinsic rhythm of discharge activity and receive input from the retina. The SCN is considered the body’s master clock, but it has multiple connections with other hypothalamic nuclei.

      Body temperature control is mainly under the control of the preoptic, anterior, and posterior nuclei, which have temperature-sensitive neurons. As the temperature goes above 37ºC, warm-sensitive neurons are activated, triggering parasympathetic activity to promote heat loss. As the temperature goes below 37ºC, cold-sensitive neurons are activated, triggering sympathetic activity to promote conservation of heat.

      The hypothalamus also plays a role in regulating prolactin secretion. Dopamine is tonically secreted by dopaminergic neurons that project from the arcuate nucleus of the hypothalamus into the anterior pituitary gland via the tuberoinfundibular pathway. The dopamine that is released acts on lactotrophic cells through D2-receptors, inhibiting prolactin synthesis. In the absence of pregnancy of lactation, prolactin is constitutively inhibited by dopamine. Dopamine antagonists result in hyperprolactinemia, while dopamine agonists inhibit prolactin secretion.

      In summary, the hypothalamus is a complex structure that regulates various bodily functions, including circadian rhythms, body temperature, and prolactin secretion. Dysfunction of the hypothalamus can lead to various disorders, such as sleep-rhythm disorder, diabetes insipidus, hyperprolactinemia, and obesity.

    • This question is part of the following fields:

      • Neurosciences
      7.3
      Seconds
  • Question 9 - What is a true statement about the planum temporale? ...

    Incorrect

    • What is a true statement about the planum temporale?

      Your Answer: It is bordered posteriorly and laterally by Heschl's gyrus

      Correct Answer: Planum temporale asymmetry is more prominent in males than in females

      Explanation:

      Cerebral Asymmetry in Planum Temporale and its Implications in Language and Auditory Processing

      The planum temporale, a triangular region in the posterior superior temporal gyrus, is a highly lateralized brain structure involved in language and music processing. Studies have shown that the planum temporale is up to ten times larger in the left cerebral hemisphere than the right, with this asymmetry being more prominent in men. This asymmetry can be observed in gestation and is present in up to 70% of right-handed individuals.

      Recent research suggests that the planum temporale also plays an important role in auditory processing, specifically in representing the location of sounds in space. However, reduced planum temporale asymmetry has been observed in individuals with dyslexia, stuttering, and schizophrenia. These findings highlight the importance of cerebral asymmetry in the planum temporale and its implications in language and auditory processing.

    • This question is part of the following fields:

      • Neurosciences
      13.7
      Seconds
  • Question 10 - A hoarse voice and difficulty swallowing (dysphagia) are symptoms of a lesion in...

    Correct

    • A hoarse voice and difficulty swallowing (dysphagia) are symptoms of a lesion in which cranial nerve?

      Your Answer: Vagus

      Explanation:

      Lesions of the vagus nerve commonly result in the following symptoms: a raspy of weak voice, difficulty swallowing, absence of the gag reflex, deviation of the uvula away from the affected side, and an inability to elevate the palate.

      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
      4.7
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  • Question 11 - What brain structure is involved in the reward system and receives dopaminergic input...

    Correct

    • What brain structure is involved in the reward system and receives dopaminergic input from the ventral tegmental area through the mesolimbic dopamine pathway?

      Your Answer: Nucleus accumbens

      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.

    • This question is part of the following fields:

      • Neurosciences
      16.8
      Seconds
  • Question 12 - What substance hinders the secretion of growth hormone in the brain? ...

    Correct

    • What substance hinders the secretion of growth hormone in the brain?

      Your Answer: Somatostatin

      Explanation:

      Pancreatic Hormones: Functions and Production

      The pancreas serves as both an exocrine and endocrine gland. Its endocrine function involves the production of four distinct hormones from the islets of Langerhans. These hormones include somatostatin, insulin, pancreatic polypeptide, and glucagon. Somatostatin is also produced by the brain, specifically the hypothalamus, where it inhibits the secretion of thyroid-stimulating hormone and growth hormone from somatotroph cells.

    • This question is part of the following fields:

      • Neurosciences
      4.5
      Seconds
  • Question 13 - Which substance is 5-HIAA a metabolite of? ...

    Correct

    • Which substance is 5-HIAA a metabolite of?

      Your Answer: Serotonin

      Explanation:

      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
      2.4
      Seconds
  • Question 14 - What is a true statement about the falx cerebri? ...

    Correct

    • What is a true statement about the falx cerebri?

      Your Answer: It is a layer of dura mater which separates the two cerebral hemispheres

      Explanation:

      Dura Mater

      The dura mater is one of the three membranes, known as meninges, that cover the brain and spinal cord. It is the outermost and most fibrous layer, with the pia mater and arachnoid mater making up the remaining layers. The pia mater is the innermost layer.

      The dura mater is folded at certain points, including the falx cerebri, which separates the two cerebral hemispheres of the brain, the tentorium cerebelli, which separates the cerebellum from the cerebrum, the falx cerebelli, which separates the cerebellar hemispheres, and the sellar diaphragm, which covers the pituitary gland and forms a roof over the hypophyseal fossa.

    • This question is part of the following fields:

      • Neurosciences
      13.8
      Seconds
  • Question 15 - Which process breaks down dopamine? ...

    Correct

    • Which process breaks down dopamine?

      Your 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
      7.8
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  • Question 16 - What waveform represents a frequency range of 8-12Hz? ...

    Correct

    • What waveform represents a frequency range of 8-12Hz?

      Your Answer: Alpha

      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 17 - What is the neuroanatomical structure that was named after a seahorse due to...

    Correct

    • What is the neuroanatomical structure that was named after a seahorse due to its alleged resemblance?

      Your Answer: Hippocampus

      Explanation:

      Brain Structures and Their Etymologies

      The hippocampus, with its swirling shape, was named after the seahorse, combining the Greek words ‘hippos’ (horse) and ‘kampos’ (sea-monster). Meanwhile, the cerebellum, which resembles a smaller version of the brain, was named after the Latin word for ‘little brain’. The corpus callosum, a bundle of nerve fibers connecting the two hemispheres of the brain, was named after the Latin for ‘tough body’. The hypothalamus, located below the thalamus, was named after its position. Finally, the putamen, a structure involved in movement control, comes from the Latin word for ‘that which falls off in pruning’. These etymologies provide insight into the history and development of our understanding of the brain’s structures.

    • This question is part of the following fields:

      • Neurosciences
      5.6
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  • Question 18 - 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: Increased delta waves

      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
      40.9
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  • Question 19 - What is the entity responsible for producing myelin in the central nervous system?...

    Correct

    • What is the entity responsible for producing myelin in the central nervous system?

      Your Answer: Oligodendrocyte

      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
      3.6
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  • Question 20 - What is the accurate statement about the pathology of schizophrenia? ...

    Correct

    • What is the accurate statement about the pathology of schizophrenia?

      Your Answer: Brain volume of affected individuals is often reduced

      Explanation:

      While ventricular enlargement is often observed in individuals with schizophrenia, it is not a definitive indicator of the condition as it can also be present in other disorders.

      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
      14.5
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  • Question 21 - An elevation in Brain-derived neurotrophic factor levels in cortical regions compared to healthy...

    Correct

    • An elevation in Brain-derived neurotrophic factor levels in cortical regions compared to healthy individuals has been observed for which of the following disorders?

      Your Answer: Schizophrenia

      Explanation:

      Neurotrophins: Crucial for Neuronal Growth and Development

      Neurotrophins are essential for the growth and development of neurons. However, disturbances in neurotrophic factors may contribute to some neurodevelopmental aspects of schizophrenia and major depression.

      Studies have shown that patients with schizophrenia have increased concentrations of Brain-derived neurotrophic factor (BDNF) in cortical areas, but decreased levels in the hippocampus compared to controls. Additionally, patients with schizophrenia have lower concentrations of neurotrophin-3 in frontal and parietal areas than controls.

      These findings suggest that neurotrophins play a critical role in the pathophysiology of schizophrenia and major depression. Further research is needed to fully understand the mechanisms underlying these disturbances in neurotrophic factors.

    • This question is part of the following fields:

      • Neurosciences
      13.6
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  • Question 22 - Which of the following eosinophilic inclusion bodies are observed as a neuropathological discovery...

    Correct

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

      Your 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
      12.2
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  • Question 23 - What is a true statement about Wernicke's aphasia? ...

    Correct

    • What is a true statement about Wernicke's aphasia?

      Your Answer: Speech is characteristically meaningless

      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
      15.5
      Seconds
  • Question 24 - Which of the following does not align with a diagnosis of frontotemporal lobar...

    Incorrect

    • Which of the following does not align with a diagnosis of frontotemporal lobar degeneration?

      Your Answer: Senile plaques

      Correct Answer: Pronounced parietal lobe atrophy

      Explanation:

      Frontotemporal lobar degeneration results in the specific shrinking of the frontal and temporal lobes.

      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.

    • This question is part of the following fields:

      • Neurosciences
      7.7
      Seconds
  • Question 25 - What type of lesion is most likely to cause bitemporal hemianopia? ...

    Correct

    • What type of lesion is most likely to cause bitemporal hemianopia?

      Your Answer: Pituitary tumour

      Explanation:

      Bitemporal hemianopia is a condition in which an individual experiences a loss of vision in the outer (temporal of lateral) half of both their left and right visual fields. This condition is typically caused by damage to the optic chiasm.

      Cerebral Dysfunction: Lobe-Specific Features

      When the brain experiences dysfunction, it can manifest in various ways depending on the affected lobe. In the frontal lobe, dysfunction can lead to contralateral hemiplegia, impaired problem solving, disinhibition, lack of initiative, Broca’s aphasia, and agraphia (dominant). The temporal lobe dysfunction can result in Wernicke’s aphasia (dominant), homonymous upper quadrantanopia, and auditory agnosia (non-dominant). On the other hand, the non-dominant parietal lobe dysfunction can lead to anosognosia, dressing apraxia, spatial neglect, and constructional apraxia. Meanwhile, the dominant parietal lobe dysfunction can result in Gerstmann’s syndrome. Lastly, occipital lobe dysfunction can lead to visual agnosia, visual illusions, and contralateral homonymous hemianopia.

    • This question is part of the following fields:

      • Neurosciences
      4.2
      Seconds
  • Question 26 - Which of the following is an amino acid neurotransmitter? ...

    Correct

    • Which of the following is an amino acid neurotransmitter?

      Your Answer: Gamma-aminobutyric acid (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
      8.7
      Seconds
  • Question 27 - Which condition has been eliminated due to the use of highly active antiretroviral...

    Incorrect

    • Which condition has been eliminated due to the use of highly active antiretroviral therapy (HAART) in individuals who are HIV positive?

      Your Answer: PML (progressive multifocal leukoencephalopathy)

      Correct Answer: Toxoplasmosis

      Explanation:

      The use of HAART has led to a complete elimination of new cases of toxoplasmosis in individuals who are HIV positive. Studies conducted on the Edinburgh cohort have revealed a significant decrease in the occurrence of CMV by 50% during autopsy, a 68% reduction in HIVE, and complete eradication of toxoplasmosis. However, there has been a slight increase in the incidence of PML and lymphoma in this group and other samples.

    • This question is part of the following fields:

      • Neurosciences
      9.9
      Seconds
  • Question 28 - The pineal gland secretes which of the following? ...

    Correct

    • The pineal gland secretes which of the following?

      Your 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
      4.4
      Seconds
  • Question 29 - A 50-year-old woman comes to the clinic with complaints of memory problems, frequent...

    Incorrect

    • A 50-year-old woman comes to the clinic with complaints of memory problems, frequent falls, and disrupted REM sleep. What is the most probable diagnosis?

      Your Answer: Progressive supranuclear palsy

      Correct Answer: Lewy body dementia

      Explanation:

      In addition to fluctuating cognition and visual hallucinations, Lewy body dementia often involves sensitivity to neuroleptics. Patients may also experience falls and REM sleep disorder as common symptoms.

    • This question is part of the following fields:

      • Neurosciences
      36.3
      Seconds
  • Question 30 - Which one of these organs is not classified as a circumventricular organ? ...

    Correct

    • Which one of these organs is not classified as a circumventricular organ?

      Your Answer: The olive

      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
      16.2
      Seconds
  • Question 31 - Which of the following is not considered a characteristic of Klüver-Bucy syndrome? ...

    Correct

    • Which of the following is not considered a characteristic of Klüver-Bucy syndrome?

      Your Answer: Visual apraxia

      Explanation:

      Kluver-Bucy Syndrome: Causes and Symptoms

      Kluver-Bucy syndrome is a neurological disorder that results from bilateral medial temporal lobe dysfunction, particularly in the amygdala. This condition is characterized by a range of symptoms, including hyperorality (a tendency to explore objects with the mouth), hypersexuality, docility, visual agnosia, and dietary changes.

      The most common causes of Kluver-Bucy syndrome include herpes, late-stage Alzheimer’s disease, frontotemporal dementia, trauma, and bilateral temporal lobe infarction. In some cases, the condition may be reversible with treatment, but in others, it may be permanent and require ongoing management. If you of someone you know is experiencing symptoms of Kluver-Bucy syndrome, it is important to seek medical attention promptly to determine the underlying cause and develop an appropriate treatment plan.

    • This question is part of the following fields:

      • Neurosciences
      7.8
      Seconds
  • Question 32 - Which symptom is unlikely to be the first one noticed in a person...

    Incorrect

    • Which symptom is unlikely to be the first one noticed in a person with normal pressure hydrocephalus?

      Your Answer: Dementia

      Correct Answer: Headache

      Explanation:

      Headache and other symptoms commonly associated with hydrocephalus may not be present in normal pressure hydrocephalus due to the fact that intracranial pressure does not typically remain elevated.

      Normal Pressure Hydrocephalus

      Normal pressure hydrocephalus is a type of chronic communicating hydrocephalus, which occurs due to the impaired reabsorption of cerebrospinal fluid (CSF) by the arachnoid villi. Although the CSF pressure is typically high, it remains within the normal range, and therefore, it does not cause symptoms of high intracranial pressure (ICP) such as headache and nausea. Instead, patients with normal pressure hydrocephalus usually present with a classic triad of symptoms, including incontinence, gait ataxia, and dementia, which is often referred to as wet, wobbly, and wacky. Unfortunately, this condition is often misdiagnosed as Parkinson’s of Alzheimer’s disease.

      The classic triad of normal pressure hydrocephalus, also known as Hakim’s triad, includes gait instability, urinary incontinence, and dementia. On the other hand, non-communicating hydrocephalus results from the obstruction of CSF flow in the third of fourth ventricle, which causes symptoms of raised intracranial pressure, such as headache, vomiting, hypertension, bradycardia, altered consciousness, and papilledema.

    • This question is part of the following fields:

      • Neurosciences
      16.9
      Seconds
  • Question 33 - Which statement about the glossopharyngeal nerve is false? ...

    Correct

    • Which statement about the glossopharyngeal nerve is false?

      Your 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
      31
      Seconds
  • Question 34 - Through which opening in the skull does the cranial nerve exit, which is...

    Correct

    • Through which opening in the skull does the cranial nerve exit, which is known as the internal auditory canal?

      Your Answer: Vestibulocochlear (VIII)

      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.

    • This question is part of the following fields:

      • Neurosciences
      9.4
      Seconds
  • Question 35 - What is another term for 'intrinsic activity' when referring to drug/receptor interactions? ...

    Correct

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

      Your 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
      14.1
      Seconds
  • Question 36 - Which of the options below does not belong to the category of small...

    Correct

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

      Your 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
      13.4
      Seconds
  • Question 37 - Your consultant calls you into his room to show you an interesting case....

    Correct

    • 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: 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
      14.9
      Seconds
  • Question 38 - Which pathway's dopamine blockade is responsible for the antipsychotic-induced extrapyramidal side effects? ...

    Correct

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

      Your 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.

    • This question is part of the following fields:

      • Neurosciences
      6.9
      Seconds
  • Question 39 - What is the primary neurotransmitter in the brain that has an inhibitory effect?...

    Correct

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

      Your 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
      4.7
      Seconds
  • Question 40 - Which of the following ocular presentations is atypical for multiple sclerosis? ...

    Incorrect

    • Which of the following ocular presentations is atypical for multiple sclerosis?

      Your Answer: Unilateral visual loss

      Correct Answer: Raised intraocular pressure

      Explanation:

      There is no correlation between multiple sclerosis and raised intraocular pressure, which is known as glaucoma when accompanied by visual field loss.

      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
      12.3
      Seconds
  • Question 41 - What was the first neurotransmitter to be recognized? ...

    Correct

    • What was the first neurotransmitter to be recognized?

      Your Answer: Acetylcholine

      Explanation:

      Henry Dale was the first to identify acetylcholine in 1915 through its effects on cardiac tissue, and he was awarded the Nobel Prize in Medicine in 1936 alongside Otto Loewi for their work. Arvid Carlsson discovered dopamine as a neurotransmitter in 1957, while von Euler discovered noradrenaline (also known as norepinephrine) as both a hormone and neurotransmitter in 1946. Oxytocin is typically classified as a hormone, while substance P is a neuropeptide that functions as both a neurotransmitter and neuromodulator and was first discovered in 1931.

    • This question is part of the following fields:

      • Neurosciences
      9.4
      Seconds
  • Question 42 - What is the other structure that, along with the putamen, comprises the lenticular...

    Correct

    • What is the other structure that, along with the putamen, comprises the lenticular nucleus?

      Your Answer: Globus pallidus

      Explanation:

      The Edinger-Westphal nucleus is the motor nucleus of the third cranial nerve, while the putamen and globus pallidus comprise the lenticular nucleus, which is part of the basal ganglia. The basal ganglia play a role in motor control and use the inhibitory neurotransmitter GABA. The components of the basal ganglia can be classified in various ways, with the corpus striatum (caudate nucleus, putamen, nucleus accumbens, and globus pallidus) and the striatum of neostriatum (caudate, putamen, and globus pallidus) being common groupings.

    • This question is part of the following fields:

      • Neurosciences
      6.1
      Seconds
  • Question 43 - What is the condition that is identified by the presence of Papp-Lantos bodies?...

    Incorrect

    • What is the condition that is identified by the presence of Papp-Lantos bodies?

      Your Answer: Pick's disease

      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
      10
      Seconds
  • Question 44 - An agitated elderly patient requires restraint. Following the restraint, your examination of the...

    Correct

    • An agitated elderly patient requires restraint. Following the restraint, your examination of the patient reveals an inability to shrug the shoulders. Which nerve is most likely to have been damaged?

      Accessory

      91%

      Hypoglossal

      4%

      Abducent

      4%

      Oculomotor

      0%

      Glossopharyngeal

      1%

      This elderly patient has most likely suffered a traumatic injury to the accessory nerve.

      Your Answer: Accessory

      Explanation:

      It is probable that this individual has experienced a traumatic injury affecting the accessory nerve.

      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
      15.5
      Seconds
  • Question 45 - Which reflex involves the oculomotor, trochlear, and abducent nerve in its motor component?...

    Incorrect

    • Which reflex involves the oculomotor, trochlear, and abducent nerve in its motor component?

      Your Answer: Accommodation

      Correct Answer: Vestibulo-ocular

      Explanation:

      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.

    • This question is part of the following fields:

      • Neurosciences
      22.7
      Seconds
  • Question 46 - What is the term used to describe the condition where a person cannot...

    Correct

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

      Your 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
      5.1
      Seconds
  • Question 47 - What statement accurately describes the trigeminal nerve? ...

    Correct

    • What statement accurately describes the trigeminal nerve?

      Your Answer: It is a mixed nerve with both sensory and motor functions

      Explanation:

      The trigeminal nerve, which is the largest cranial nerve, serves both sensory and motor functions. It is composed of three primary branches, namely the ophthalmic, maxillary, and mandibular branches. This nerve is responsible for providing sensory information to the face and head, while also controlling the muscles involved in chewing. On the other hand, the facial nerve is responsible for controlling the muscles that enable facial expressions and transmitting information from the front two-thirds of the tongue.

      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
      38.1
      Seconds
  • Question 48 - What is the neurotransmitter that encourages sleep? ...

    Incorrect

    • What is the neurotransmitter that encourages sleep?

      Your Answer: Serotonin

      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
      26.5
      Seconds
  • Question 49 - Which statement accurately describes neurofibrillary tangles? ...

    Correct

    • Which statement accurately describes neurofibrillary tangles?

      Your Answer: They are also seen in dementia pugilistica

      Explanation:

      Amyloid protein is the primary component of amyloid plaques, although they are most commonly linked to Alzheimer’s disease.

      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
      51.5
      Seconds
  • Question 50 - What is the neural mechanism that plays a crucial role in drug addiction...

    Correct

    • What is the neural mechanism that plays a crucial role in drug addiction by processing specific information about past experiences and the environment?

      Your Answer: Nucleus accumbens

      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.

    • This question is part of the following fields:

      • Neurosciences
      12.9
      Seconds
  • Question 51 - What substance is combined with choline to produce acetylcholine? ...

    Correct

    • What substance is combined with choline to produce acetylcholine?

      Your Answer: Acetyl coenzyme A

      Explanation:

      The enzyme choline acetyltransferase facilitates the production of acetylcholine by catalyzing the combination of choline and Acetyl coenzyme A.

      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
      7.1
      Seconds
  • Question 52 - What is the closest estimate of the membrane potential of a cell at...

    Correct

    • What is the closest estimate of the membrane potential of a cell at rest?

      Your Answer: -70 mV

      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
      3.7
      Seconds
  • Question 53 - What is a characteristic that is shared by both upper and lower motor...

    Correct

    • What is a characteristic that is shared by both upper and lower motor neuron lesions?

      Your Answer: Weakness

      Explanation:

      Motor Neuron Lesions

      Signs of an upper motor neuron lesion include weakness, increased reflexes, increased tone (spasticity), mild atrophy, an upgoing plantar response (Babinski reflex), and clonus. On the other hand, signs of a lower motor neuron lesion include atrophy, weakness, fasciculations, decreased reflexes, and decreased tone. It is important to differentiate between the two types of lesions as they have different underlying causes and require different treatment approaches. A thorough neurological examination can help identify the location and extent of the lesion, which can guide further diagnostic testing and management.

    • This question is part of the following fields:

      • Neurosciences
      11.4
      Seconds
  • Question 54 - A 65-year-old individual presents with a sudden onset of horizontal diplopia. Upon examination,...

    Correct

    • A 65-year-old individual presents with a sudden onset of horizontal diplopia. Upon examination, you note that they have an inability to move their left eye laterally. Which cranial nerve is most likely affected?

      Your Answer: VI

      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.

    • This question is part of the following fields:

      • Neurosciences
      17.8
      Seconds
  • Question 55 - What is the most common subtype of Creutzfeldt-Jakob disease (CJD) that is responsible...

    Correct

    • What is the most common subtype of Creutzfeldt-Jakob disease (CJD) that is responsible for the majority of cases?

      Your Answer: sCJDMM1 and sCJDMV1

      Explanation:

      CJD has several subtypes, including familial (fCJD), iatrogenic (iCJD), sporadic (sCJD), and new variant (vCJD). The most common subtype is sCJD, which makes up 85% of cases. sCJD can be further classified based on the MV polymorphisms at codon 129 of the PRNP gene, with sCJDMM1 and sCJDMV1 being the most prevalent subtypes. fCJD is the most common subtype after sCJD, while vCJD and iCJD are rare and caused by consuming contaminated food of tissue contamination from other humans, respectively.

    • This question is part of the following fields:

      • Neurosciences
      10.4
      Seconds
  • Question 56 - Which area of the brain is responsible for causing hemiballismus when it is...

    Correct

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

      Your 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
      5.5
      Seconds
  • Question 57 - Which waves are present at the onset of stage 2 sleep, in addition...

    Correct

    • Which waves are present at the onset of stage 2 sleep, in addition to k-complexes?

      Your Answer: Sigma

      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
      8.7
      Seconds
  • Question 58 - What are some common symptoms that are typically observed in the initial phases...

    Correct

    • What are some common symptoms that are typically observed in the initial phases of Alzheimer's disease?

      Your Answer: Hippocampal atrophy

      Explanation:

      The medial temporal lobe, comprising the hippocampus and parahippocampal gyrus, exhibits the earliest neuropathological alterations.

      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
      8.5
      Seconds
  • Question 59 - During which stage of sleep do sleep spindles appear on an EEG in...

    Correct

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

      Your 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
      3
      Seconds
  • Question 60 - Which interleukin has been consistently found to be present in higher levels in...

    Incorrect

    • Which interleukin has been consistently found to be present in higher levels in individuals with depression compared to those without depression?

      Your Answer: IL-2

      Correct Answer: IL-6

      Explanation:

      Inflammatory Cytokines and Mental Health

      Research has suggested that an imbalance in the immune system, particularly the pro-inflammatory cytokines, may play a significant role in the development of common mental disorders. The strongest evidence is found in depression, where studies have shown increased levels of inflammatory markers, such as interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), and c-reactive protein (CRP), in depressed individuals compared to healthy controls (Santoft, 2020).

      While most studies have focused on the differences in inflammatory markers between depressed and healthy individuals, some have also found a correlation between higher levels of inflammation and more severe depressive symptoms. The underlying cause of this chronic low-grade inflammation is not yet fully understood, but potential factors include psychosocial stress, physical inactivity, poor diet, smoking, obesity, altered gut permeability, disturbed sleep, and vitamin D deficiency.

    • This question is part of the following fields:

      • Neurosciences
      7.1
      Seconds
  • Question 61 - In which condition is the presence of regular, rapid, and generalized spike and...

    Correct

    • In which condition is the presence of regular, rapid, and generalized spike and wave activity observed?

      Your Answer: Myoclonic epilepsy

      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
      5.6
      Seconds
  • Question 62 - Which brain structure is located next to Broca's and Wernicke's areas? ...

    Correct

    • Which brain structure is located next to Broca's and Wernicke's areas?

      Your Answer: Sylvian sulcus

      Explanation:

      Understanding the sylvian (lateral) sulcus is crucial in comprehending the perisylvian language area and distinguishing between perisylvian and extrasylvian types of aphasias.

      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
      17.7
      Seconds
  • Question 63 - A researcher studying early childhood development is interested in the formation of the...

    Correct

    • A researcher studying early childhood development is interested in the formation of the nervous system. What is the initial step in the development of the nervous system?

      Your Answer: Formation of the neural groove

      Explanation:

      The nervous system in embryos develops from the neural plate, which is a thickening of the ectoderm. The first step in this process is the formation of the neural groove, which is then surrounded by neural folds. These folds gradually come together and fuse to form the neural tube. The neural crest, which is made up of parts of the neural ectoderm, is formed from the rolled-up sides of the neural tube and helps in the development of the peripheral nervous system. The mesencephalon, of midbrain, is formed from the second vesicle of the neural tube. This process of neural development is essential for the proper functioning of the nervous system in later life.

    • This question is part of the following fields:

      • Neurosciences
      23.1
      Seconds
  • Question 64 - What is a true statement about the endocannabinoid system? ...

    Correct

    • What is a true statement about the endocannabinoid system?

      Your Answer: CB2 receptors are expressed at much lower levels in the central nervous system compared to CB1

      Explanation:

      The Endocannabinoid System and its Role in Psychosis

      The endocannabinoid system (ECS) plays a crucial role in regulating various physiological functions in the body, including cognition, sleep, energy metabolism, and inflammation. It is composed of endogenous cannabinoids, cannabinoid receptors, and proteins that transport, synthesize, and degrade endocannabinoids. The two best-characterized cannabinoid receptors are CB1 and CB2, which primarily couple to inhibitory G proteins and modulate different neurotransmitter systems in the brain.

      Impairment of the ECS after cannabis consumption has been linked to an increased risk of psychotic illness. However, enhancing the ECS with cannabidiol (CBD) has shown anti-inflammatory and antipsychotic outcomes in both healthy study participants and in preliminary clinical trials on people with psychotic illness of at high risk of developing psychosis. Studies have also found increased anandamide levels in the cerebrospinal fluid and blood, as well as increased CB1 expression in peripheral immune cells of people with psychotic illness compared to healthy controls. Overall, understanding the role of the ECS in psychosis may lead to new therapeutic approaches for treating this condition.

    • This question is part of the following fields:

      • Neurosciences
      6.8
      Seconds
  • Question 65 - Which type of channel opening in the plasma membrane leads to the depolarization...

    Correct

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

      Your 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
      7.4
      Seconds
  • Question 66 - What SPECT finding is indicative of Alzheimer's disease? ...

    Correct

    • What SPECT finding is indicative of Alzheimer's disease?

      Your Answer: Decreased temporal perfusion

      Explanation:

      Given the medial temporal lobe atrophy commonly observed in Alzheimer’s disease, a reduction in perfusion of the temporal lobe would be anticipated.

      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
      10.2
      Seconds
  • Question 67 - Which condition is most likely to exhibit a hyperkinetic gait? ...

    Correct

    • Which condition is most likely to exhibit a hyperkinetic gait?

      Your Answer: Sydenham chorea

      Explanation:

      Gait disorders can be caused by a variety of conditions, including neurological, muscular, and structural abnormalities. One common gait disorder is hemiplegic gait, which is characterized by unilateral weakness on the affected side, with the arm flexed, adducted, and internally rotated, and the leg on the same side in extension with plantar flexion of the foot and toes. When walking, the patient may hold their arm to one side and drag their affected leg in a semicircle (circumduction) due to weakness of leg flexors and extended foot. Hemiplegic gait is often seen in patients who have suffered a stroke.

      Other gait disorders include ataxic gait, spastic gait, and steppage gait, each with their own unique characteristics and associated conditions. Accurate diagnosis and treatment of gait disorders is important for improving mobility and quality of life for affected individuals.

    • This question is part of the following fields:

      • Neurosciences
      9.3
      Seconds
  • Question 68 - Which neuroimaging technique measures the amount of oxygenated hemoglobin in the blood? ...

    Correct

    • Which neuroimaging technique measures the amount of oxygenated hemoglobin in the blood?

      Your Answer: Functional magnetic resonance imaging (fMRI)

      Explanation:

      Functional Imaging Techniques

      Functional imaging techniques are used to study brain activity by detecting changes in blood flow and oxygenation levels. One such technique is functional magnetic resonance imaging (fMRI), which measures the concentration of oxygenated haemoglobin in the blood. When neural activity increases in a specific area of the brain, blood flow to that area increases, leading to a higher concentration of haemoglobin.

      Magnetic resonance imaging (MRI) is another technique that uses magnetic fields to create images of the brain’s structure. Magnetic resonance spectroscopy (MRS) is a related technique that can detect several odd-numbered nuclei.

      To obtain a more accurate anatomical location for functional information, single photon emission computed tomography (SPECT) and positron emission tomography (PET) are used. SPECT and PET both provide information about brain activity by detecting the emission of particles. However, SPECT emits a single particle, while PET emits two particles. These techniques are useful for studying brain function in both healthy individuals and those with neurological disorders.

    • This question is part of the following fields:

      • Neurosciences
      22
      Seconds
  • Question 69 - What is the enzyme that breaks down APP into harmless protein fragments? ...

    Correct

    • What is the enzyme that breaks down APP into harmless protein fragments?

      Your Answer: Alpha-secretase

      Explanation:

      Alpha-Secretase: A Potential Treatment for Alzheimer’s Disease

      Alpha-secretase is a promising avenue for preventing and treating Alzheimer’s disease. When amyloid precursor protein (APP) crosses the cell membrane, it can be cleaved by various enzymes. Alpha-secretase cleaves APP in a way that produces non-toxic protein fragments. However, beta and gamma-secretase are two other enzymes that can cleave APP, resulting in shorter, stickier fragments called beta-amyloid. These fragments can join together to form insoluble amyloid plaques. Researchers are developing drugs that can either stimulate alpha-secretase of block beta- and gamma-secretase, with the hope of preventing or treating Alzheimer’s disease.

    • This question is part of the following fields:

      • Neurosciences
      3.4
      Seconds
  • Question 70 - If a man experiences a severe road traffic accident resulting in substantial damage...

    Correct

    • If a man experiences a severe road traffic accident resulting in substantial damage to his frontal lobe, what symptoms would you anticipate him to exhibit?

      Your Answer: Contralateral hemiplegia

      Explanation:

      Cerebral Dysfunction: Lobe-Specific Features

      When the brain experiences dysfunction, it can manifest in various ways depending on the affected lobe. In the frontal lobe, dysfunction can lead to contralateral hemiplegia, impaired problem solving, disinhibition, lack of initiative, Broca’s aphasia, and agraphia (dominant). The temporal lobe dysfunction can result in Wernicke’s aphasia (dominant), homonymous upper quadrantanopia, and auditory agnosia (non-dominant). On the other hand, the non-dominant parietal lobe dysfunction can lead to anosognosia, dressing apraxia, spatial neglect, and constructional apraxia. Meanwhile, the dominant parietal lobe dysfunction can result in Gerstmann’s syndrome. Lastly, occipital lobe dysfunction can lead to visual agnosia, visual illusions, and contralateral homonymous hemianopia.

    • This question is part of the following fields:

      • Neurosciences
      34.5
      Seconds
  • Question 71 - Which type of white matter tract is categorized as a commissural tract? ...

    Correct

    • Which type of white matter tract is categorized as a commissural tract?

      Your Answer: Corpus callosum

      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
      11.1
      Seconds
  • Question 72 - Which statement about variant CJD is accurate? ...

    Correct

    • Which statement about variant CJD is accurate?

      Your Answer: It is associated with the pulvinar sign on the MRI

      Explanation:

      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
      26
      Seconds
  • Question 73 - What is the name of the hormone secreted by the gastrointestinal tract that...

    Correct

    • What is the name of the hormone secreted by the gastrointestinal tract that triggers the sensation of hunger?

      Your Answer: Ghrelin

      Explanation:

      Appetite Control Hormones

      The regulation of appetite is influenced by various hormones in the body. Neuropeptide Y, which is produced by the hypothalamus, stimulates appetite. On the other hand, leptin, which is produced by adipose tissue, suppresses appetite. Ghrelin, which is mainly produced by the gut, increases appetite. Cholecystokinin (CCK), which is also produced by the gut, reduces appetite. These hormones play a crucial role in maintaining a healthy balance of food intake and energy expenditure.

    • This question is part of the following fields:

      • Neurosciences
      9.1
      Seconds
  • Question 74 - Which of the following is not a component of the syndrome of frontotemporal...

    Correct

    • Which of the following is not a component of the syndrome of frontotemporal lobe degeneration (FTLD)?

      Your Answer: Posterior cortical atrophy

      Explanation:

      Frontotemporal lobe degeneration (FTLD) encompasses various syndromes, such as Pick’s disease, primary progressive aphasia (which impacts speech), semantic dementia (affecting conceptual knowledge), and corticobasal degeneration (characterized by asymmetrical akinetic-rigid syndrome and apraxia). It is important to note that posterior cortical atrophy, which involves tissue loss in the posterior regions and affects higher visual processing, is not considered a part of the FTLD syndrome.

    • This question is part of the following fields:

      • Neurosciences
      13.8
      Seconds
  • Question 75 - Which symptom is most commonly associated with occlusion of the anterior cerebral artery?...

    Incorrect

    • Which symptom is most commonly associated with occlusion of the anterior cerebral artery?

      Your Answer: Contralateral hemiplegia of arm more than leg

      Correct Answer: Transcortical motor aphasia

      Explanation:

      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
      9.3
      Seconds
  • Question 76 - 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: Right frontal lobe

      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
      42.2
      Seconds
  • Question 77 - A 42 year old, overweight woman presents with recurring episodes of one-sided vision...

    Correct

    • 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: 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
      39.6
      Seconds
  • Question 78 - Which structure is not included in the neocortex? ...

    Correct

    • Which structure is not included in the neocortex?

      Your 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
      20
      Seconds
  • Question 79 - What is the enzyme responsible for deactivating acetylcholine? ...

    Correct

    • What is the enzyme responsible for deactivating acetylcholine?

      Your Answer: Acetylcholinesterase

      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
      6.2
      Seconds
  • Question 80 - In what type of epilepsy is it most common to experience an aura?...

    Correct

    • In what type of epilepsy is it most common to experience an aura?

      Your Answer: Temporal lobe

      Explanation:

      This question is presented in two variations on the exam, with one implying that auras are primarily linked to temporal lobe epilepsy and the other to complex partial seizures. In reality, partial seizures are most commonly associated with auras compared to other types of seizures. While partial seizures can originate in any lobe of the brain, those that arise in the temporal lobe are most likely to produce an aura. Therefore, both versions of the question are accurate.

      Epilepsy and Aura

      An aura is a subjective sensation that is a type of simple partial seizure. It typically lasts only a few seconds and can help identify the site of cortical onset. There are eight recognized types of auras, including somatosensory, visual, auditory, gustatory, olfactory, autonomic, abdominal, and psychic.

      In about 80% of cases, auras precede temporal lobe seizures. The most common auras in these seizures are abdominal and psychic, which can cause a rising epigastric sensation of feelings of fear, déjà vu, of jamais vu. Parietal lobe seizures may begin with a contralateral sensation, usually of the positive type, such as an electrical sensation of tingling. Occipital lobe seizures may begin with contralateral visual changes, such as colored lines, spots, of shapes, of even a loss of vision. Temporal-parietal-occipital seizures may produce more formed auras.

      Complex partial seizures are defined by impairment of consciousness, which means decreased responsiveness and awareness of oneself and surroundings. During a complex partial seizure, a patient is unresponsive and does not remember events that occurred.

    • This question is part of the following fields:

      • Neurosciences
      4.2
      Seconds
  • Question 81 - In what area of the brain does the Anton-Babinski syndrome cause damage? ...

    Correct

    • In what area of the brain does the Anton-Babinski syndrome cause damage?

      Your Answer: Occipital lobe

      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
      13.2
      Seconds
  • Question 82 - From which substance is gamma-aminobutyric acid synthesized? ...

    Correct

    • From which substance is gamma-aminobutyric acid synthesized?

      Your Answer: Glutamate

      Explanation:

      Glutamate is the precursor for the synthesis of GABA.

      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
      8.3
      Seconds
  • Question 83 - What is located within Brodmann area 22? ...

    Correct

    • What is located within Brodmann area 22?

      Your 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
      4.1
      Seconds
  • Question 84 - What type of dysarthria is typically caused by widespread damage to the upper...

    Correct

    • What type of dysarthria is typically caused by widespread damage to the upper motor neurons?

      Your Answer: Spastic 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
      4.8
      Seconds
  • Question 85 - Which structure is most likely to show signs of atrophy in a patient...

    Correct

    • Which structure is most likely to show signs of atrophy in a patient with Alzheimer's disease?

      Your Answer: Hippocampus

      Explanation:

      Alzheimer’s disease often results in the shrinkage of the hippocampus, which is a component of the limbic system and is responsible for the formation and retention of long-term memories.

      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
      7.5
      Seconds
  • Question 86 - In the field of neurology, which specific region of the brain did the...

    Correct

    • In the field of neurology, which specific region of the brain did the case of Phineas Gage contribute to our understanding of?

      Your Answer: Frontal lobe

      Explanation:

      The Case of Phineas Gage and the Importance of the Frontal Lobe

      Phineas Gage was a railroad worker who experienced a traumatic accident where an iron pole went through his frontal lobe. Despite surviving the incident, his personality underwent a significant change. This case was crucial in advancing our knowledge of the frontal lobe’s function.

    • This question is part of the following fields:

      • Neurosciences
      5.3
      Seconds
  • Question 87 - What condition is most commonly associated with slow (<2.5 Hz) generalized spike-and-wave discharges...

    Correct

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

      Your 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
      24.2
      Seconds
  • Question 88 - When activated, which type of receptor increases the permeability of a plasma membrane...

    Correct

    • When activated, which type of receptor increases the permeability of a plasma membrane to chloride ions?

      Your Answer: GABA-A

      Explanation:

      GABA-A is the sole ionotropic receptor among the options provided. Its function involves the selective conduction of chloride ions across the cell membrane upon activation by GABA, leading to hyperpolarization of the neuron.

      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
      7
      Seconds
  • Question 89 - With what condition of disease are Hirano bodies commonly linked? ...

    Correct

    • With what condition of disease are Hirano bodies commonly linked?

      Your Answer: Alzheimer's

      Explanation:

      Hirano bodies are considered to be a general indication of neuronal degeneration and are primarily observed in cases of Alzheimer’s disease.

      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
      4.2
      Seconds
  • Question 90 - In which region of the brain are most dopamine neurons found? ...

    Correct

    • In which region of the brain are most dopamine neurons found?

      Your Answer: Substantia nigra

      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
      12.4
      Seconds
  • Question 91 - Can you identify the brain structure that is not found in both cerebral...

    Correct

    • Can you identify the brain structure that is not found in both cerebral hemispheres?

      Your Answer: Pineal gland

      Explanation:

      Neuroanatomical Structures

      The pineal gland is a unique structure in the brain that is not present bilaterally. It is a small endocrine gland responsible for producing melatonin, a hormone derived from serotonin. Along with the pituitary gland and circumventricular organs, the pineal gland is one of the few unpaired structures in the brain.

      In contrast, the caudate nucleus is a paired structure located within the basal ganglia. It is present bilaterally and plays a crucial role in motor control and learning.

      The midbrain contains the Mammillary body, which is also a paired structure involved in long-term memory formation. These structures work together to help us remember and recall past experiences.

      Finally, the supraoptic nucleus is duplicated in each cerebral hemisphere. This structure is involved in regulating water balance and plays a critical role in maintaining homeostasis in the body.

    • This question is part of the following fields:

      • Neurosciences
      30.8
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  • Question 92 - A 62-year-old man experiences a stroke caused by a ruptured berry aneurysm in...

    Incorrect

    • A 62-year-old man experiences a stroke caused by a ruptured berry aneurysm in the middle cerebral artery, resulting in damage to the temporal lobe. What tests would you anticipate to show abnormalities?

      Your Answer: Semantic memory

      Correct Answer: Copying intersecting pentagons

      Explanation:

      When the parietal lobe is not functioning properly, it can cause constructional apraxia. This condition makes it difficult for individuals to replicate the intersecting pentagons, which is a common cognitive test included in Folstein’s mini-mental state examination.

    • This question is part of the following fields:

      • Neurosciences
      32.2
      Seconds
  • Question 93 - To which category does the dentate gyrus belong? ...

    Correct

    • To which category does the dentate gyrus belong?

      Your Answer: Hippocampus

      Explanation:

      The dentate gyrus is a component of the hippocampal formation.

      A gyrus is a ridge on the cerebral cortex, and there are several important gyri to be aware of in exams. These include the angular gyrus in the parietal lobe for language, mathematics, and cognition; the cingulate gyrus adjacent to the corpus callosum for emotion, learning, and memory; the fusiform gyrus in the temporal lobe for face and body recognition, as well as word and number recognition; the precentral gyrus in the frontal lobe for voluntary movement control; the postcentral gyrus in the parietal lobe for touch; the lingual gyrus in the occipital lobe for dreaming and word recognition; the superior frontal gyrus in the frontal lobe for laughter and self-awareness; the superior temporal gyrus in the temporal lobe for language and sensation of sound; the parahippocampal gyrus surrounding the hippocampus for memory; and the dentate gyrus in the hippocampus for the formation of episodic memory.

    • This question is part of the following fields:

      • Neurosciences
      11.9
      Seconds
  • Question 94 - What street drug inhibits the monoamine transporter SERT? ...

    Correct

    • What street drug inhibits the monoamine transporter SERT?

      Your Answer: Amphetamine

      Explanation:

      Cannabis attaches to cannabinoid receptors, while heroin acts as an opioid agonist and alters the function of dopamine.

      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
      10.1
      Seconds
  • Question 95 - What is the stage of sleep that is identified by hypnic jerks and...

    Correct

    • What is the stage of sleep that is identified by hypnic jerks and theta waves on the EEG?

      Your Answer: Stage I

      Explanation:

      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
      16.8
      Seconds
  • Question 96 - What is the accuracy of the dopamine hypothesis in explaining schizophrenia? ...

    Incorrect

    • What is the accuracy of the dopamine hypothesis in explaining schizophrenia?

      Your Answer: Elevated presynaptic dopamine synthesis has not been demonstrated

      Correct Answer: Cannabinoid agonists have been shown in animals to increase striatal dopamine release

      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
      35.4
      Seconds
  • Question 97 - What distinguishing characteristics indicate a diagnosis of dissociative non-epileptic attacks (pseudoseizures) instead of...

    Correct

    • What distinguishing characteristics indicate a diagnosis of dissociative non-epileptic attacks (pseudoseizures) instead of generalized tonic-clonic seizures?

      Your Answer: Gradual onset of episode

      Explanation:

      The presence of a gradual onset may indicate non-epileptic attacks, while other symptoms suggest genuine generalised tonic clonic seizures. Additional characteristics of pseudoseizures include a higher incidence in females (8:1), a history of previous illness behavior, and childhood physical and/of sexual abuse. Diagnosis can be challenging, but video EEG can be a useful tool in confirming the presence of pseudoseizures.

    • This question is part of the following fields:

      • Neurosciences
      21.5
      Seconds
  • Question 98 - What is the main producer of serotonin in the brain? ...

    Correct

    • What is the main producer of serotonin in the brain?

      Your Answer: Raphe nuclei

      Explanation:

      The pituitary gland is situated in the sella turcica, while the suprachiasmatic nucleus regulates circadian rhythms. Serotonin release in the brain is primarily sourced from the neurons of the raphe nuclei, which are located along the midline of the brainstem. The choroid plexus produces cerebrospinal fluid, and enterochromaffin cells in the gut contain the majority of the body’s serotonin.

    • This question is part of the following fields:

      • Neurosciences
      5.1
      Seconds
  • Question 99 - What is a true statement about Broca's aphasia? ...

    Correct

    • What is a true statement about Broca's aphasia?

      Your Answer: Main areas affected are Brodmann areas 44 and 45

      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
      9.4
      Seconds
  • Question 100 - In which region of the brain is the ventral tegmental area situated? ...

    Correct

    • In which region of the brain is the ventral tegmental area situated?

      Your Answer: Midbrain

      Explanation:

      The Role of the Ventral Tegmental Area in Reward and Pleasure

      The midbrain contains a cluster of dopaminergic cells known as the ventral tegmental area (VTA), which plays a crucial role in the experience of reward and pleasure. These cells are involved in the release of dopamine, a neurotransmitter that is associated with feelings of pleasure and motivation. The VTA is activated in response to various stimuli, such as food, sex, and drugs, and is responsible for the pleasurable sensations that accompany these experiences. Dysfunction in the VTA has been linked to addiction and other disorders related to reward processing. Understanding the role of the VTA in reward and pleasure is essential for developing effective treatments for these conditions.

    • This question is part of the following fields:

      • Neurosciences
      6.6
      Seconds

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