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Question 1
Incorrect
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A 22-year-old man presents to his GP complaining of ankle pain. He has been training for a marathon and running up to 60 miles per week. During the examination, he experiences difficulty flexing his four lateral toes. The GP suspects tenosynovitis affecting his flexor digitorium longus.
Which other muscles are part of the affected leg compartment?Your Answer: Tibialis anterior, extensor digitorum longus, peroneus tertius and extensor hallucis longus
Correct Answer: Tibialis posterior, flexor hallucis longus, and popliteus
Explanation:The muscles located in the deep posterior compartment include the Tibialis posterior, Flexor hallucis longus, Flexor digitorum longus, and Popliteus. The Flexor digitorum longus muscle is specifically affected in this compartment.
Muscular Compartments of the Lower Limb
The lower limb is composed of different muscular compartments that perform various actions. The anterior compartment includes the tibialis anterior, extensor digitorum longus, peroneus tertius, and extensor hallucis longus muscles. These muscles are innervated by the deep peroneal nerve and are responsible for dorsiflexing the ankle joint, inverting and evert the foot, and extending the toes.
The peroneal compartment, on the other hand, consists of the peroneus longus and peroneus brevis muscles, which are innervated by the superficial peroneal nerve. These muscles are responsible for eversion of the foot and plantar flexion of the ankle joint.
The superficial posterior compartment includes the gastrocnemius and soleus muscles, which are innervated by the tibial nerve. These muscles are responsible for plantar flexion of the foot and may also flex the knee.
Lastly, the deep posterior compartment includes the flexor digitorum longus, flexor hallucis longus, and tibialis posterior muscles, which are innervated by the tibial nerve. These muscles are responsible for flexing the toes, flexing the great toe, and plantar flexion and inversion of the foot, respectively.
Understanding the muscular compartments of the lower limb is important in diagnosing and treating injuries and conditions that affect these muscles. Proper identification and management of these conditions can help improve mobility and function of the lower limb.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 2
Incorrect
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You examine a patient who suffered a severe stroke two years prior.
What clinical examination features would you anticipate observing?Your Answer: Hypotonia
Correct Answer: Increased deep tendon reflexes
Explanation:If there is an increased reflex response, it may indicate an upper motor neuron lesion. This type of lesion can be caused by a stroke and can result in spastic weakness and heightened reflex responses. The reason for hyperreflexia is due to the loss of inhibitory signals that normally regulate spinal reflex circuits. On the other hand, a lower motor neuron lesion will cause flaccid weakness, reduced deep tendon reflexes, fasciculations, and muscle atrophy.
Reflexes are automatic responses that our body makes in response to certain stimuli. These responses are controlled by the nervous system and do not require conscious thought. There are several common reflexes that are associated with specific roots in the spinal cord. For example, the ankle reflex is associated with the S1-S2 root, while the knee reflex is associated with the L3-L4 root. Similarly, the biceps reflex is associated with the C5-C6 root, and the triceps reflex is associated with the C7-C8 root. Understanding these reflexes can help healthcare professionals diagnose and treat certain conditions.
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This question is part of the following fields:
- Neurological System
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Question 3
Correct
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A 65-year-old woman with chronic kidney failure has been instructed by her nephrologist to adhere to a 'renal diet'. She visits you to gain more knowledge about this.
What is typically recommended to individuals with chronic kidney disease?Your Answer: Low potassium diet
Explanation:Dietary Recommendations for Chronic Kidney Disease Patients
Chronic kidney disease patients are recommended to follow a specific diet that is low in protein, phosphate, sodium, and potassium. This dietary advice is given to reduce the strain on the kidneys, as these substances are typically excreted by the kidneys. By limiting the intake of these nutrients, patients can help slow the progression of their kidney disease and manage their symptoms more effectively. It is important for patients to work closely with their healthcare provider or a registered dietitian to ensure they are meeting their nutritional needs while following these dietary restrictions. With proper guidance and adherence to this diet, patients with chronic kidney disease can improve their overall health and quality of life.
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This question is part of the following fields:
- Renal System
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Question 4
Incorrect
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A woman is expecting a baby with Down's syndrome. At the routine 22-week scan, a congenital anomaly was detected. The doctor explained to her and her partner that the defect resolves spontaneously in approximately 50% of cases but can present with a pansystolic murmur after birth. What is the probable congenital defect being described?
Your Answer: Atrial septal defect
Correct Answer: Ventricular septal defect
Explanation:Understanding Ventricular Septal Defect
Ventricular septal defect (VSD) is a common congenital heart disease that affects many individuals. It is caused by a hole in the wall that separates the two lower chambers of the heart. In some cases, VSDs may close on their own, but in other cases, they require specialized management.
There are various causes of VSDs, including chromosomal disorders such as Down’s syndrome, Edward’s syndrome, Patau syndrome, and cri-du-chat syndrome. Congenital infections and post-myocardial infarction can also lead to VSDs. The condition can be detected during routine scans in utero or may present post-natally with symptoms such as failure to thrive, heart failure, hepatomegaly, tachypnea, tachycardia, pallor, and a pansystolic murmur.
Management of VSDs depends on the size and symptoms of the defect. Small VSDs that are asymptomatic may require monitoring, while moderate to large VSDs may result in heart failure and require nutritional support, medication for heart failure, and surgical closure of the defect.
Complications of VSDs include aortic regurgitation, infective endocarditis, Eisenmenger’s complex, right heart failure, and pulmonary hypertension. Eisenmenger’s complex is a severe complication that results in cyanosis and clubbing and is an indication for a heart-lung transplant. Women with pulmonary hypertension are advised against pregnancy as it carries a high risk of mortality.
In conclusion, VSD is a common congenital heart disease that requires specialized management. Early detection and appropriate treatment can prevent severe complications and improve outcomes for affected individuals.
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This question is part of the following fields:
- Cardiovascular System
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Question 5
Incorrect
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An 80-year-old woman with a history of hypertension is brought to the emergency department after falling at home. She reports experiencing a loss of sensation on her right side.
Upon examination, you confirm the loss of sensation in the right arm and leg. Additionally, you note that the right arm has 3/5 power and the right leg has 2/5 power. In contrast, the limbs on the left side have 5/5 power and intact sensation.
Based on these findings, which artery is most likely affected?Your Answer: Superior cerebellar artery
Correct Answer: Anterior cerebral artery
Explanation:The patient is experiencing contralateral hemiparesis and sensory loss, with the lower extremity being more affected than the upper. This suggests that the stroke is likely affecting the anterior cerebral artery. Other symptoms that may occur with this type of stroke include behavioral abnormalities and incontinence.
If the basilar artery is occluded, the patient may experience locked-in syndrome, which results in paralysis of all voluntary muscles except for those controlling eye movements.
A stroke affecting the middle cerebral artery would typically result in more severe effects on the face and arm, rather than the leg. Other symptoms may include speech and visual deficits.
A stroke affecting the posterior cerebral artery would primarily affect vision, resulting in contralateral homonymous hemianopia.
Cerebellar infarcts, such as those affecting the superior cerebellar artery, can be difficult to diagnose as they often present with non-specific symptoms such as nausea, vomiting, headache, and dizziness.
Stroke can affect different parts of the brain depending on which artery is affected. If the anterior cerebral artery is affected, the person may experience weakness and loss of sensation on the opposite side of the body, with the lower extremities being more affected than the upper. If the middle cerebral artery is affected, the person may experience weakness and loss of sensation on the opposite side of the body, with the upper extremities being more affected than the lower. They may also experience vision loss and difficulty with language. If the posterior cerebral artery is affected, the person may experience vision loss and difficulty recognizing objects.
Lacunar strokes are a type of stroke that are strongly associated with hypertension. They typically present with isolated weakness or loss of sensation on one side of the body, or weakness with difficulty coordinating movements. They often occur in the basal ganglia, thalamus, or internal capsule.
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This question is part of the following fields:
- Neurological System
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Question 6
Correct
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A 45-year-old woman has been referred to a specialist neurology clinic due to ongoing muscle stiffness and rigidity affecting her lower back, shoulders, neck, and hips, which has been progressively worsening over the past year. Additionally, she experiences muscle spasms in her legs when exposed to loud noises or stress. Her medical history includes pernicious anaemia and Hashimoto's thyroiditis. The doctor suspects Stiff person syndrome and plans to initiate benzodiazepine therapy to manage her symptoms.
What is the underlying cause of this woman's symptoms, which are attributed to low levels of a specific neurotransmitter?Your Answer: GABA
Explanation:Stiff person syndrome is a condition that arises due to the presence of autoantibodies against the glutamic acid decarboxylase (GAD) enzyme. This enzyme plays a crucial role in the synthesis of gamma-aminobutyric acid (GABA), a neurotransmitter that helps to regulate muscle contractions. When GAD is attacked by autoantibodies, GABA levels in the central nervous system (CNS) decrease, leading to increased signaling to muscles and resulting in muscle stiffness and spasms.
The fact that the neurologist wants to prescribe benzodiazepines as a treatment for this condition is another indication that GABA may be the neurotransmitter involved. Benzodiazepines are known to be GABA agonists, which means that they can help to replace the low levels of GABA in the CNS and counteract the excitatory signaling caused by glutamate.
In contrast, Parkinson’s disease is characterized by low levels of dopamine, which would not be expected to cause the symptoms seen in stiff person syndrome.
Understanding GABA as the Principal Inhibitory Neurotransmitter of the Cortex
GABA, or gamma-aminobutyric acid, is a crucial neurotransmitter that plays a significant role in regulating brain activity. It is considered the principal inhibitory neurotransmitter of the cortex, which means that it helps to reduce the activity of neurons in this region of the brain. This is important because excessive neuronal activity can lead to seizures, anxiety, and other neurological disorders.
GABA is produced in a region of the brain called the substantia nigra pars reticulata. This area is responsible for regulating movement and is also involved in the production of dopamine, another important neurotransmitter. GABA is released by neurons in the cortex and binds to specific receptors on other neurons, which helps to reduce their activity.
The importance of GABA in the brain cannot be overstated. It is involved in a wide range of functions, including sleep, anxiety, and mood regulation. It is also a target for many drugs used to treat neurological disorders, such as epilepsy and anxiety. Understanding the role of GABA in the brain is crucial for developing new treatments for these conditions and improving our overall understanding of brain function.
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This question is part of the following fields:
- General Principles
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Question 7
Correct
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A 54-year-old male presents to the hospital with a chief complaint of central chest pain, accompanied by nausea and sweating that has been ongoing for two hours. After eight hours of the onset of the pain, the following result is obtained:
Troponin T 30.8 ug/L (<10)
What is the probable diagnosis?Your Answer: Myocardial infarction
Explanation:Elevated Troponin T as a Marker of Cardiac Injury
This patient’s troponin T concentration is significantly elevated, indicating cardiac injury. Troponin T is a component of the cardiac myocyte and is normally undetectable. Elevated levels of troponin T are highly specific to cardiac injury and are more reliable than creatinine kinase, which is less specific. Troponin T levels increase in acute coronary syndromes, myocarditis, and myocardial infarction.
In this patient’s case, the elevated troponin T suggests a myocardial infarction (MI) due to the symptoms presented. Troponin T can be detected within a few hours of an MI and peaks at 14 hours after the onset of pain. It may peak again several days later and remain elevated for up to 10 days. Therefore, it is a good test for acute MI but not as reliable for recurrent MI in the first week. CK-MB may be useful in this case as it starts to rise 10-24 hours after an MI and disappears after three to four days.
Other conditions that may present with similar symptoms include aortic dissection, which causes tearing chest pain that often radiates to the back with hypotension. ECG changes are not always present. Myocarditis causes chest pain that improves with steroids or NSAIDs and a rise in troponin levels, with similar ECG changes to a STEMI. There may also be reciprocal lead ST depression and PR depression. Pulmonary embolism presents with shortness of breath, pleuritic chest pain, hypoxia, and hemoptysis. Pericardial effusion presents with similar symptoms to pericarditis, with Kussmaul’s sign typically present.
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This question is part of the following fields:
- Cardiovascular System
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Question 8
Incorrect
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An 80-year-old woman arrives at the Emergency Department reporting painless loss of vision on the right side that started 30 minutes ago. Based on the history and examination, it is probable that she has experienced an ophthalmic artery stroke. Which branch of the Circle of Willis is likely affected?
Your Answer: Basilar artery
Correct Answer: Internal carotid artery
Explanation:The ophthalmic artery originates from the internal carotid artery, which is part of the Circle of Willis, a circular network of arteries that supply the brain. The anterior cerebral arteries, which supply the frontal and parietal lobes, as well as the corpus callosum and cingulate cortex of the brain, also arise from the internal carotid artery. A stroke of the ophthalmic artery or its branch, the central retinal artery, can cause painless loss of vision. The basilar artery, which forms part of the posterior cerebral circulation, is formed from the convergence of the two vertebral arteries and gives rise to many arteries, but not the ophthalmic artery. The posterior cerebral artery, which supplies the occipital lobe, arises from the basilar artery.
The Circle of Willis is an anastomosis formed by the internal carotid arteries and vertebral arteries on the bottom surface of the brain. It is divided into two halves and is made up of various arteries, including the anterior communicating artery, anterior cerebral artery, internal carotid artery, posterior communicating artery, and posterior cerebral arteries. The circle and its branches supply blood to important areas of the brain, such as the corpus striatum, internal capsule, diencephalon, and midbrain.
The vertebral arteries enter the cranial cavity through the foramen magnum and lie in the subarachnoid space. They then ascend on the anterior surface of the medulla oblongata and unite to form the basilar artery at the base of the pons. The basilar artery has several branches, including the anterior inferior cerebellar artery, labyrinthine artery, pontine arteries, superior cerebellar artery, and posterior cerebral artery.
The internal carotid arteries also have several branches, such as the posterior communicating artery, anterior cerebral artery, middle cerebral artery, and anterior choroid artery. These arteries supply blood to different parts of the brain, including the frontal, temporal, and parietal lobes. Overall, the Circle of Willis and its branches play a crucial role in providing oxygen and nutrients to the brain.
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This question is part of the following fields:
- Cardiovascular System
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Question 9
Incorrect
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A 23-year-old man was diagnosed with maturity-onset diabetes of the young (MODY) type 1 and has been on an oral anti-diabetic agent for the past year. What is the mechanism of action of the drug he is most likely taking?
Your Answer: Inhibition of hepatic glucose production and increased peripheral glucose uptake in skeletal muscle
Correct Answer: Binding to ATP-dependent K+ channel on the pancreatic beta cell membrane
Explanation:The patient is likely taking a sulfonylurea medication, which works by binding to the ATP-dependent K+ channel on the pancreatic beta-cell membrane to promote endogenous insulin secretion. This is the recommended first-line treatment for patients with MODY type 1, as their genetic defect results in reduced insulin secretion. Thiazolidinediones (glitazones) activate peroxisome proliferator-activated receptor-gamma (PPARĪ³) and are not typically used in this population. Metformin (biguanide class) inhibits hepatic glucose production and increases peripheral uptake, but is less effective than sulfonylureas in MODY type 1. Acarbose inhibits intestinal alpha-glucosidase and is not used in MODY patients. Dipeptidyl peptidase-4 inhibitors (gliptins) are commonly used in type 2 diabetes but are not first-line treatment for MODY.
Sulfonylureas are a type of medication used to treat type 2 diabetes mellitus. They work by increasing the amount of insulin produced by the pancreas, but only if the beta cells in the pancreas are functioning properly. Sulfonylureas bind to a specific channel on the cell membrane of pancreatic beta cells, known as the ATP-dependent K+ channel (KATP).
While sulfonylureas can be effective in managing diabetes, they can also cause some adverse effects. The most common side effect is hypoglycemia, which is more likely to occur with long-acting preparations like chlorpropamide. Another common side effect is weight gain. However, there are also rarer side effects that can occur, such as hyponatremia (low sodium levels) due to inappropriate ADH secretion, bone marrow suppression, hepatotoxicity (liver damage), and peripheral neuropathy.
It is important to note that sulfonylureas should not be used during pregnancy or while breastfeeding.
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This question is part of the following fields:
- Endocrine System
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Question 10
Incorrect
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A 56-year-old man presents to the neurologist with a complaint of progressive gait disturbance over the past few months. He has no significant medical history and has not seen a healthcare professional in many years due to his busy schedule. He reports a painless lesion on his penile shaft that resolved spontaneously many years ago. His family history is unremarkable, and he travels frequently for business, consuming two glasses of wine per week. He maintains a balanced diet.
During the examination, the patient exhibits a slamming of his feet onto the ground while walking. There is no dysdiadochokinesis, past-pointing, or nystagmus. His peripheral sensation is intact, and his motor function is normal. Upon examination of his cranial nerves, the neurologist notes small pupils that do not respond to light but contract normally to accommodation and convergence.
What is the most likely diagnosis, and which anatomic location's lesions are contributing to his gait disturbance?Your Answer: Spinothalamic tracts
Correct Answer: Dorsal column of the spinal cord
Explanation:Tabes dorsalis is a manifestation of tertiary syphilis that results in the degeneration of dorsal column fibers. This patient exhibits two key features of the disease, including a sensory ataxic gait (also known as a stomping gait) and Argyll-Robertson pupils, which are bilaterally small and reactive but do not accommodate. A diagnosis of tertiary syphilis can be confirmed by testing the spinal fluid with VDRL or RPR.
While lesions of the cerebellar vermis can also cause gait ataxia, it typically presents as a truncal ataxia rather than a stomping gait. Additionally, the pupillary findings make neurosyphilis more likely.
A lesion of the lateral corticospinal tract would result in suboptimal motor function on neurological examination, and Argyll-Robertson pupils would not be consistent with this answer.
Destruction of the anterior white commissure of the spinothalamic tract is seen in syringomyelia, which presents with bilateral loss of pain and temperature rather than gait disturbance.
Although a disturbance of the vestibulocochlear nerve can result in gait unsteadiness, a stomping gait would not be the typical manifestation, and the pupillary findings make this answer less likely.
Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. The infection progresses through primary, secondary, and tertiary stages, with an incubation period of 9-90 days. The primary stage is characterized by a painless ulcer at the site of sexual contact, along with local lymphadenopathy. Women may not always exhibit visible symptoms. The secondary stage occurs 6-10 weeks after primary infection and presents with systemic symptoms such as fevers and lymphadenopathy, as well as a rash on the trunk, palms, and soles. Other symptoms may include buccal ulcers and genital warts. Tertiary syphilis can lead to granulomatous lesions of the skin and bones, ascending aortic aneurysms, general paralysis of the insane, tabes dorsalis, and Argyll-Robertson pupil. Congenital syphilis can cause blunted upper incisor teeth, linear scars at the angle of the mouth, keratitis, saber shins, saddle nose, and deafness.
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This question is part of the following fields:
- General Principles
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