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Question 1
Correct
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Injury to the supraspinatus muscle will affect:
Your Answer: Initiation of abduction of the humerus
Explanation:This muscle arises from the medial two-thirds of the supraspinatus fossa and from the supraspinatus fascia. It is inserted into the highest impression on the greater tubercle of the humerus after passing over the upper part of the shoulder joint. It works with the deltoid to raise the arm from the side of the trunk and initiate abduction. It also assists in fixation of the head of the humerus in the glenoid cavity.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 2
Incorrect
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A 32-year old gentleman came to the emergency department, complaining of progressively increasing weakness in his arms and legs over 5 days. On examination, there is symmetrical weakness on both sides of his face, along with weakness of the proximal and distal muscles of all four limbs. No loss of sensation noted. Deep tendon reflexes could not be elicited and plantar responses were downward. On enquiry, it was revealed that he had an upper respiratory tract infection 10 days ago. The likely diagnosis is:
Your Answer: Myasthenia gravis
Correct Answer: Guillain–Barré syndrome
Explanation:Guillain–Barré syndrome (GBS) is an acute, autoimmune polyradiculoneuropathy which affects the peripheral nervous system and is usually triggered by an acute infectious process. 75% patients have a history of acute infection within the past 1–4 weeks, usually respiratory or gastrointestinal. immunisations have also been implicated. The most common form is acute inflammatory demyelinating polyneuropathy. It results in an ascending paralysis with complete loss of deep tendon reflexes. Treatment includes immunoglobulins and supportive care. However, the disease may be fatal due to severe pulmonary complications and dysautonomia.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 3
Incorrect
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The muscle which has an antagonistic action to the serratus anterior muscle and is the primary protractor of the scapula is the?
Your Answer: Pectoralis minor
Correct Answer: Rhomboid major
Explanation:The rhomboid major arises from the second, third, fourth and fifth thoracic vertebrae. It is inserted into a narrow tendinous arch attached to the root of the spine of the scapula and the inferior angle. By its insertion in the inferior angle of the scapula, it acts on this angle and produces a slight rotation of the scapula on the side of the chest. It also retracts the scapula by working with the trapezius muscle.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 4
Incorrect
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Normally, the O2 transfer in the lungs from alveolar to capillary is perfusion-limited. In which of the following situations does it become a diffusion-limited process?
Your Answer: Chronic obstructive lung disease
Correct Answer: Pulmonary oedema
Explanation:Normally, the transfer of oxygen from air spaces to blood takes place across the alveolar-capillary membrane by simple diffusion and depends entirely on the amount of blood flow (perfusion-limited process). Diseases that affect this diffusion will transform the normal process to a diffusion limited process. Thus, the diseases which cause a thickened barrier (such as pulmonary oedema due to increased extravascular lung water or asbestosis) will limit the diffusion of oxygen. Chronic obstructive lung diseases will have little effect on diffusion. Inhaling hyperbaric gas mixtures might overcome the diffusion limitation in patients with mild asbestosis or interstitial oedema, by increasing the driving force. Strenuous (not mild) exercise might also favour diffusion limitation and decrease passage time. Increasing the rate of ventilation will not have this affect but will only maintain a high oxygen gradient from air to blood.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 5
Correct
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A 55-year-old woman died 3 years after a cardiac transplant due to worsening congestive heart failure. Autopsy revealed diffuse hyperplasia of the vascular intima involving the entire length of the coronary arteries. The most probable cause of deterioration of the cardiac function is:
Your Answer: Coronary atherosclerosis
Explanation:Allograft coronary artery disease (CAD) can begin right after the transplant and is the major cause of later death in cardiac transplant recipients. This form of atherosclerosis progresses quickly resulting in allograft failure. Due to lack of premonitory symptoms CAD may lead to sudden death.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 6
Incorrect
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Injury to this nerve may result in loss of sensation of the mandibular teeth and bone:
Your Answer: Greater palatine nerve
Correct Answer: Inferior alveolar nerve
Explanation:The inferior alveolar nerve (sometimes called the inferior dental nerve) is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve. The inferior alveolar nerves supply sensation to the lower teeth of the mandible.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 7
Incorrect
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The dura mater is a thick membrane that is the outermost of the three layers of the meninges. Which of the following foramen transmits the dura mater?
Your Answer: Foramen spinosum
Correct Answer: Foramen magnum
Explanation:The foramen magnum is found in the most inferior part of the posterior cranial fossa . It is traversed by vital structures including the medulla oblongata . Its contents include the following: medulla oblongata, meninges (arachnoid, dura and pia mater), spinal root of the accessory nerve, vertebral arteries, anterior and posterior spinal arteries, tectorial membrane and alar ligaments .
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 8
Correct
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A 55-year old patient with signs and symptoms of internal haemorrhage was brought in for emergency surgery to control the bleeding. Angiography results revealed an advanced duodenal tumour that had perforated the blood vessel immediately behind the first part of the duodenum. Which of the following is the most likely blood vessel that was ruptured by the cancer?
Your Answer: Gastroduodenal artery
Explanation:The gastroduodenal artery is the artery that lies just behind the first portion of the duodenum. The gastroduodenal artery would be the most likely artery to be perforated by a cancer in this area. The perforation is as a result of the spillage of the acidic content of the chyme in the duodenum. All the other blood vessels in the list would less likely be affected by the gastric expellant from the duodenum. The coronary vein is located in the lesser curvature of the stomach. The inferior pancreaticoduodenal arcade is located inferiorly to the first part of the duodenum on the head of the pancreas. The hepatic artery proper is a branch of the common hepatic artery that is located superior to the first portion of the duodenum. The splenic vein arises from the spleen; it forms the portal vein by joining the superior mesenteric vein. It is laterally detached from the duodenum. Both the left gastric vein and the splenic vein are located superior to the first portion of the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 9
Incorrect
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A patient is admitted to the ICU, and is prescribed tazobactam, amongst other drugs. What is the mechanism of action of tazobactam?
Your Answer: Inhibits calcineurin
Correct Answer: Inhibits beta-lactamase
Explanation:Tazobactam is a compound which inhibits the action of bacterial beta-lactamases. It is added to the extended-spectrum beta-lactam antibiotic piperacillin to broaden the spectrum of piperacillin by making it effective against organisms that express beta-lactamase and would normally degrade piperacillin.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 10
Incorrect
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A 68-year-old woman complains of headaches, dizziness, and memory loss. About a month ago, she fell from a staircase but only suffered mild head trauma. What is the most likely diagnosis in this case?
Your Answer: Intracerebral haematoma
Correct Answer: Chronic subdural haematoma
Explanation:A quarter to a half of patients with chronic subdural haematoma have no identifiable history of head trauma. If a patient does have a history of head trauma, it usually is mild. The average time between head trauma and chronic subdural haematoma diagnosis is 4–5 weeks. Symptoms include decreased level of consciousness, balance problems, cognitive dysfunction and memory loss, motor deficit (e.g. hemiparesis), headache or aphasia. Some patients present acutely. They usually result from tears in bridging veins which cross the subdural space, and may cause an increase in intracranial pressure (ICP).
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This question is part of the following fields:
- Neurology
- Pathology
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Question 11
Incorrect
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What causes a reduction in pulmonary functional residual capacity?
Your Answer: Emphysema
Correct Answer: Pulmonary fibrosis
Explanation:Pulmonary functional residual capacity (FRC) is = volume of air present in the lungs at the end of passive expiration.
Obstructive diseases (e.g. emphysema, chronic bronchitis, asthma) = an increase in FRC due to an increase in lung compliance and air trapping.
Restrictive diseases (e.g. pulmonary fibrosis) result in stiffer, less compliant lungs and a reduction in FRC.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 12
Incorrect
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A 34-year old gentleman presented with acute pancreatitis to the emergency department. On enquiry, there was found to be a history of recurrent pancreatitis, eruptive xanthomas and raised plasma triglyceride levels associated with chylomicrons. Which of the following will be found deficient in this patient?
Your Answer: Low-density lipoprotein (LDL) receptors
Correct Answer: Lipoprotein lipase
Explanation:The clinical features mentioned here suggest the diagnosis of hypertriglyceridemia due to lipoprotein lipase (LPL) deficiency. LPL aids in hydrolysing the lipids in lipoproteins into free fatty acids and glycerol. Apo-CII acts as a co-factor. Deficiency of this enzyme leads to hypertriglyceridemia.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 13
Incorrect
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What will the destruction of endoplasmic reticulum stop?
Your Answer: Synthesis of glycogen
Correct Answer: Synthesis of proteins
Explanation:The rough endoplasmic reticulum is the factory for the manufacturing of proteins. It contains ribosomes attached to it and transports proteins that are destined for membranes and secretions. The rough ER is connected to the nuclear envelope and to the cisternae of the Golgi apparatus by vesicles that shuttle between the two compartments.
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This question is part of the following fields:
- General
- Physiology
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Question 14
Incorrect
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What is the likely course of a pulmonary embolism arising from the leg veins and ending in the apical segmental pulmonary artery that supplies the superior lobe of left lung?.
Your Answer: Inferior vena cava – right atrium – tricuspid valve – right ventricle – pulmonary trunk – left pulmonary artery – left bronchial artery – left apical segmental artery
Correct Answer: Inferior vena cava – right atrium – tricuspid valve – right ventricle – pulmonary trunk – left pulmonary artery – left superior lobar artery – left apical segmental artery
Explanation:A clot originating in the leg vein will go to the inferior vena cava, into the right atrium, through the tricuspid valve, into the right ventricle, through the pulmonary trunk, into the left pulmonary artery, into the left superior lobar artery and then finally reach the left apical segmental artery.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 15
Correct
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Which foramen contains the vertebral artery?
Your Answer: Foramen magnum
Explanation:The foramen magnum is found in the most inferior part of the posterior cranial fossa. It is traversed by vital structures including the medulla oblongata. Its contents include the following: medulla oblongata, meninges, spinal root of the accessory nerve, vertebral arteries, anterior and posterior spinal arteries, tectorial membrane and alar ligaments.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 16
Correct
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A patient admitted for esophagectomy showed low levels of the lightest plasma protein in terms of weight. Which of the following is the lightest plasma protein:
Your Answer: Albumin
Explanation:Albumin is the most abundant and the lightest of all the plasma proteins. It maintains osmotic pressure, transports unconjugated bilirubin, thyroid hormones, fatty acids, drugs and acts as a buffer for pH.
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This question is part of the following fields:
- General
- Physiology
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Question 17
Correct
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What is the chief ligament preventing posterior sliding of the tibia on the femur ?
Your Answer: Posterior cruciate
Explanation:The posterior cruciate ligament is attached to the posterior intercondyloid fossa of the tibia and the lateral and front part of the medial condyle of the femur. It resists sliding of the tibia posteriorly.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 18
Correct
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Which statement is true about the inferior sagittal sinus?
Your Answer: Is formed between two layers of meningeal dura
Explanation:The inferior sagittal sinus is also known as the inferior longitudinal sinus. It courses along the inferior border of the falx cerebri, superior to the corpus callosum. It is cylindrical in shape and increases in size as it passes backward ending in the straight sinus. It receives blood from the deep and medial aspects of the cerebral hemispheres and drains into the straight sinus.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 19
Correct
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What principal artery that supplies the meninges is susceptible to rupture following trauma to the side of the head over the temporal region:
Your Answer: Middle meningeal artery
Explanation:The middle meningeal artery normally arises from the first or mandibular segment of the maxillary artery. The artery runs in a groove on the inside of the cranium, this can clearly be seen on a lateral skull X-ray. An injured middle meningeal artery is the most common cause of an epidural hematoma.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 20
Incorrect
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Which of the following physiological changes will you see in a young man who has been trekking in the Himalayas for 3 years?
Your Answer: Pulmonary vasodilatation
Correct Answer: Increased renal excretion of HCO3 –
Explanation:The atmospheric pressure is lower at high altitudes as compared with sea level. This leads to a decrease in the partial pressure of oxygen. Once 2100 m (7000 feet) of altitude is reached, there is a drop in saturation of oxyhaemoglobin. The oxygen saturation of haemoglobin determines the oxygen content in the blood. The body physiological tries to adapt to high altitude by acclimatization. Immediate effects include hyperventilation, fluid loss (due to a decreased thirst drive), increase in heart rate and slightly lowered stroke volume. Long term effects include lower lactate production, compensatory alkali loss in urine, decrease in plasma volume, increased erythropoietin release and red cell mass, increased haematocrit, higher concentration of capillaries in striated muscle tissue, increase in myoglobin, increase in mitochondria, increase in aerobic enzyme concentration such as 2,3-DPG and pulmonary vasoconstriction.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 21
Incorrect
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During a street fight a boy sustained a laceration below the elbow. It was a deep cut that led to profuse bleeding from an artery situated on the supinator muscle immediately below the elbow. The vessel most likely to have been injured is?
Your Answer: Posterior ulnar recurrent artery
Correct Answer: Radial recurrent artery
Explanation:The radial recurrent artery is situated on the supinator muscle then passing between the brachialis and the brachioradialis muscles. It originates from the radial artery and ends by anastomosing with the terminal part of the Profunda brachii.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 22
Incorrect
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During a surgical procedure involving the carotid artery, which nerve in the cervical plexus of nerves that is embedded in the carotid sheath is most susceptible to injury?
Your Answer: Spinal accessory nerve
Correct Answer: Ansa cervicalis
Explanation:The ansa cervicalis is a loop of nerves that are part of the cervical plexus. They lie superficial to the internal jugular vein in the carotid triangle. Branches from the ansa cervicalis innervate the sternohyoid, sternothyroid and the inferior belly of the omohyoid. The superior root of the ansa cervicalis is formed by a branch of spinal nerve C1. These nerve fibres travel in the hypoglossal nerve before leaving to form the superior root. The superior root goes around the occipital artery and then descends embedded in the carotid sheath. It sends a branch off to the superior belly of the omohyoid muscle and is then joined by the inferior root. The inferior root is formed by fibres from spinal nerves C2 and C3.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 23
Correct
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The stomach is an organ that is divided into several important anatomical parts. These parts of the stomach have varied arterial blood supply that ensure that the whole organ receive oxygenated blood. Which of the following arteries if ligated, will not render any portion of the stomach ischaemic?
Your Answer: Superior mesenteric
Explanation:The blood supply to the stomach is through the following arteries:
– The superior mesenteric artery supplies blood to the lower part of the duodenum, pancreas and two-thirds of the transverse colon. Thus ligation of the superior mesenteric artery would not affect the stomach.
– The right and the left gastroepiploic arteries supply the greater curvature of the stomach – along its edges.
– The short gastric artery supplies blood to the upper portion of the of the greater curvature and the fundus of the stomach.
– The gastroduodenal artery supplies blood to the distal part of the stomach (the pyloric sphincter) and the proximal end of the duodenum.
– The left gastroepiploic and the short gastric are branches of the splenic artery and therefore ligation of the splenic artery would directly affect the stomach.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 24
Incorrect
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Etoposide is a chemotherapeutic agent used in the treatment of different types of cancer. Which of the following is the correct indication for this drug?
Your Answer: Colon cancer
Correct Answer: Lung cancer
Explanation:Etoposide phosphate is an inhibitor of the enzyme topoisomerase II. It is used as a form of chemotherapy for malignancies such as lung cancer, testicular cancer, lymphoma, non-lymphocytic leukaemia and glioblastoma multiforme. Side effects are very common and can include low blood cell counts, vomiting, loss of appetite, diarrhoea, hair loss, and fever.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 25
Correct
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Which of the following cells would be increased in a patient suffering from a hydatid cyst in the liver?
Your Answer: Eosinophils
Explanation:Eosinophils are granulocytes that respond to parasitic infections. They are also involved in allergy response and asthma. They contain granules which stain red with Romanowsky’s method and contain peroxidase, Rnase, Dnase, histamine, lipase and major basic proteins that are toxic to the parasite as well as the hosts tissue. They are about 1-5% of the total WBC population and persist in the blood for 6-12 hours.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 26
Correct
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A 59-year-old woman with hyperaldosteronism is prescribed a diuretic. Which of the following diuretics promotes diuresis by opposing the action of aldosterone?
Your Answer: Potassium-sparing diuretic
Explanation:The term potassium-sparing refers to an effect rather than a mechanism or location. Potassium-sparing diuretics act by either antagonising the action of aldosterone (spironolactone) or inhibiting Na+ reabsorption in the distal tubules (amiloride). This group of drugs is often used as adjunctive therapy, in combination with other drugs, for the management of chronic heart failure. Spironolactone, the first member of the class, is also used in the management of hyperaldosteronism (including Conn’s syndrome) and female hirsutism (due to additional antiandrogen actions).
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This question is part of the following fields:
- Physiology
- Renal
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Question 27
Incorrect
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In which situation is a stretch reflex such as knee jerk likely to be exaggerated?
Your Answer: In extrapyramidal disorders like Parkinsonism
Correct Answer: In upper motor neuron lesion
Explanation:A stretch reflex is a monosynaptic reflex that causes muscle contraction in response to stretching within that muscle. The sensory apparatus in a muscle that are sensitive to stretch are the muscle spindles. The patellar (knee jerk) reflex is an example. In upper motor neuron lesions, the stretch reflexes tend to be brisk due to loss of inhibitory signals on gamma neurons through the lateral reticulospinal tract.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 28
Incorrect
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A neonate with failure to pass meconium is being evaluated. His abdomen is distended and X-ray films of the abdomen show markedly dilated small bowel and colon loops. The likely diagnosis is:
Your Answer: Multiple polyps in the colon
Correct Answer: Aganglionosis in the rectum
Explanation:Hirschsprung’s disease (also known as aganglionic megacolon) leads to colon enlargement due to bowel obstruction by an aganglionic section of bowel that starts at the anus. A blockage is created by a lack of ganglion cells needed for peristalsis that move the stool. 1 in 5000 children suffer from this disease, with boys affected four times more commonly than girls. It develops in the fetus in early stages of pregnancy. Symptoms include not having a first bowel movement (meconium) within 48 hours of birth, repeated vomiting and a swollen abdomen. Two-third of cases are diagnosed within 3 months of birth. Some children may present with delayed toilet training and some might not show symptoms till early childhood. Diagnosis is by barium enema and rectal biopsy (showing lack of ganglion cells).
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 29
Incorrect
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A Monospot test in a 17-year old boy presenting with fever, multiple palpable lymph nodes and mild icterus was positive. His blood investigation is likely to show which of the following?
Your Answer: Increased band neutrophils
Correct Answer: Atypical lymphocytosis
Explanation:Epstein-Barr virus is the causative agent for infectious mononucleosis leading to presence of atypical lymphocytes in blood. Usually symptomatic in older children and adults, the incubation period is 30-50 days. Symptoms include fatigue, followed by fever, adenopathy and pharyngitis. Fatigue can last for months and is maximum in first few weeks. Fever spikes in the afternoon or early evening, with temperature around 39.5 – 40.5 °C. The ‘typhoidal’ form where fatigue and fever predominate has a low onset and resolution. Pharyngitis resemble that due to streptococcus and can be severe and painful. Lymphadenopathy is bilaterally symmetrical and can involve any nodes, specially the cervical ones. Mild splenomegaly is seen in 50% cases, usually in 2-3rd week. Mild tender hepatomegaly can occur. Less common manifestations include maculopapular eruptions, jaundice, periorbital oedema and palatal enanthema. Diagnostic tests include full blood count and a heterophil antibody test. Morphologically abnormal lymphocytes account for 80% cells and are heterogenous, unlike leukaemia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 30
Incorrect
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During cardiac catheterisation in a 20-year old man, the following data is obtained: Pressure (mmHg), O2 saturation (%) Right atrium 7 (N = 5) 90 (N = 75), Right ventricle 35/7 (N = 25/5) 90 (N = 75), Pulmonary artery 35/8 (N = 25/15), 90 (N = 75), Left atrium 7 (N = 9) 95 (N = 95), Left ventricle 110/7 (N = 110/9) 95 (N = 95), Aorta 110/75 (N = 110/75) 95 (N = 95) where N = Normal value. What is the likely diagnosis?
Your Answer: Mitral stenosis
Correct Answer: Atrial septal defect
Explanation:A congenital heart disease, ASD or atrial septal defect leads to a communication between the right and left atria due to a defect in the interatrial septum. This leads to mixing of arterial and venous blood from the right and left side of the heart. The hemodynamic significance of this defect depends on the presence of shunting of blood. Normally, the left side of the heart has higher pressure than the right as the left side has to pump blood throughout the body. A large ASD (> 9 mm) will result in a clinically significant left-to-right shunt, causing volume overload of the right atrium and ventricle, eventually leading to heart failure. Cardiac catheterization would reveal very high oxygen saturation in the right atrium, right ventricle and pulmonary artery. Eventually, the left-to-right shunt will lead to pulmonary hypertension and increased afterload in the right ventricle, along with the increased preload due to the shunted blood. This will either cause right ventricular failure, or raise the pressure in the right side of the heart to equal or more than that in the left. Elevation of right atrial pressure to that of left atrial pressure would thus lead to diminishing or complete cessation of the shunt. If left uncorrected, there will be reversal of the shunt, known as Eisenmenger syndrome, resulting in clinical signs of cyanosis as the oxygen-poor blood form right side of the heart will mix with the blood in left side and reach the peripheral vascular system.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 31
Incorrect
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A 55-year-old woman complains of pain in the proximal and distal interphalangeal joins, and back pain which has increased over the last 4 years and worsens after activity. X-rays reveal Heberden’s and Bouchard’s nodes in her interphalangeal joints and the presence of osteophytes in her spine. What is the most likely diagnosis?
Your Answer: Gout
Correct Answer: Osteoarthritis
Explanation:Osteoarthritis is most common in older adults, predominating in women between the ages of 40 and 70; after this age, men and women are affected equally. It affects an entire joint, with disruption and potential loss of joint cartilage, along with other joint changes, including bone hypertrophy (osteophyte formation). The pain is usually gradual and is worse after activity, with occasional joint swelling. X-ray findings include marginal osteophytes, narrowing of the joint space, increased density of the subchondral bone, subchondral cyst formation, bony remodelling and joint effusions.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 32
Incorrect
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Which of the following is a true statement regarding the pupil?
Your Answer: Atropine causes pupil constriction
Correct Answer: Phentolamine causes pupil constriction
Explanation:A balance between the sympathetic tone to the radial fibres of the iris and parasympathetic tone to the pupillary sphincter muscle determines the pupil size. Phentolamine (α-adrenergic receptor blocker) causes pupillary constriction. Dilatation of the pupil occurs with increased sympathetic activity, decreased parasympathetic activity during darkness or block of muscarinic receptors by atropine.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 33
Correct
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Which antibiotic acts by inhibiting protein synthesis?
Your Answer: Erythromycin
Explanation:Penicillins and cephalosporins (e.g. cefuroxime, cefotaxime, ceftriaxone) inhibit bacterial cell wall synthesis through the inhibition of peptidoglycan cross-linking.
Macrolides (e.g. erythromycin), tetracyclines, aminoglycosides and chloramphenicol act by interfering with bacterial protein synthesis.
Sulphonamides (e.g. trimethoprim, co-trimoxazole) work by inhibiting the synthesis of nucleic acid
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This question is part of the following fields:
- Pharmacology; Microbiology
- Physiology
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Question 34
Correct
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From which branchial (pharyngeal) pouch does the inferior parathyroid gland arise?
Your Answer: 3rd
Explanation:The following structures arise from each branchial pouch:
1st pouch – eustachian tube, middle ear, mastoid, and inner layer of the tympanic membrane
2nd pouch – middle ear, palatine tonsils
3rd pouch – inferior parathyroid glands, thymus
4th pouch – superior parathyroid glands, ultimobranchial body which forms the parafollicular C-cells of the thyroid gland, musculature and cartilage of larynx (along with the sixth pharyngeal pouch)
5th pouch – rudimentary structure
6th pouch – along with the fourth pouch, contributes to the formation of the musculature and cartilage of the larynx.
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This question is part of the following fields:
- Anatomy
- Endocrine; Embryology
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Question 35
Incorrect
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What is the most likely cause of prolonged bleeding time in a 40 year old women admitted for a laparoscopic cholecystectomy?
Your Answer: Haemophilia
Correct Answer: Thrombocytopaenia
Explanation:Bleeding time is related to platelet function, thus a decrease in platelet function, as seen in thrombocytopenia, DIC and von Willebrand disease in which platelet aggregation is defective, leads to an increase in bleeding time. It is not affected by a decrease or deficiency of any other clotting factors. Aspirin and other COX inhibitors prolong bleeding time along with warfarin and heparin.
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This question is part of the following fields:
- General
- Physiology
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Question 36
Incorrect
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A 90-year-old man is prescribed spironolactone after his family notices his legs are swollen. What class of drugs does spironolactone belong to?
Your Answer: Lipid-lowering drugs
Correct Answer: Potassium-sparing diuretics
Explanation:Spironolactone is a renal competitive aldosterone antagonist in a class of drugs called ‘potassium-sparing diuretics’, that is primarily used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It is also used in the treatment of high blood pressure, low blood potassium, early-onset puberty, and acne and excessive hair growth in women. Spironolactone inhibits the effect of aldosterone by competing for intracellular aldosterone receptors in the distal tubule cells. This increases the secretion of water and sodium, while decreasing the excretion of potassium.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 37
Correct
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A 69 Year old lady presented to the emergency department following a massive myocardial infarction. She was found to be in hypotensive shock with focal neurological signs. Unfortunately the patient demised. What would be the expected findings on the brain biopsy?
Your Answer: Liquefactive necrosis
Explanation:Liquefactive necrosis is often associated with bacterial or fungal infections. However, hypoxic death of cells within the central nervous system can also result in liquefactive necrosis. The focal area is soft with a liquefied centre containing necrotic debris and dead white cells. This may later be enclosed by a cystic wall
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This question is part of the following fields:
- Cell Injury & Wound Healing; Neurology
- Pathology
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Question 38
Correct
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The dilator pupillae muscle is innervated by postganglionic sympathetic fibres. Where do the postganglionic sympathetic fibres originate?
Your Answer: Superior cervical ganglion
Explanation:The postganglionic sympathetic axons are derived from the superior cervical ganglion and innervate the eye and lacrimal gland allowing for vasoconstriction of the iris and sclera, pupillary dilation, widening of the palpebral fissure, and a reduction in tear production.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 39
Correct
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Into which vein does the left and right inferior thyroid veins drain?
Your Answer: Brachiocephalic vein
Explanation:The brachiocephalic vein is formed by the confluence of the subclavian and internal jugular veins. In addition it receives drainage from: the left and right internal thoracic veins (also called internal mammary veins), left and right inferior thyroid veins and the left superior intercostal vein.
The superior thyroid veins and middle thyroid veins drain into the internal jugular vein. The right and left inferior thyroid veins to drain into their respective brachiocephalic veins (right and left). -
This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 40
Incorrect
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Out of the given options, which of the following is the most likely diagnosis in a 25-year old gentleman presenting with a testicular germ cell tumour?
Your Answer: Leydig cell tumour
Correct Answer: Embryonal carcinoma
Explanation:Embryonal carcinoma is a non-seminomatous germ cell tumour of the testis, accounting for 25% testicular tumours. Other germ cell tumours include seminoma, teratoma and choriocarcinoma. Embryonal carcinomas are known to occur in men aged 25-35 years, and occasionally in teens. They are rarely seen in ovaries of females. It can spread to the vas deferens and also to the aortic lymph nodes. Embryonal carcinomas are known to have elements of fetal origin such as cartilage. Usually, the main tumour is about 2.5cm long, with an extension of 8-9cm along the testicular cord. Contiguous spread to the testicle is seen in less than 1% cases.
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This question is part of the following fields:
- Pathology
- Urology
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Question 41
Incorrect
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A 56 year old gentleman, who is a chronic smoker presents to the clinic with dyspnoea. His Chest X-ray shows intercostal space widening with increased blackening bilaterally. What is the most likely finding on his pulmonary function test?
Your Answer: Decreased total lung capacity
Correct Answer: Increased total lung capacity
Explanation:In patients suspected of having chronic obstructive pulmonary disease, pulmonary function testing (PFT) is useful to confirm airway obstruction, to quantify its severity and reversibility, for following disease progression and monitoring response to treatment. These tests include:
FEV1 – volume of air forcefully expired during the first second after a full breath
Forced vital capacity (FVC) – total volume of air expired with maximal force and flow-volume loops. The hallmark of airway obstruction is reduction of FEV1, FVC and the ratio of FEV1/FVC, with a concave pattern in expiratory tracing on the flow-volume loop. FEV1 and forced vital capacity (FVC) are easily measured with office spirometry and are useful to assess the severity of disease. Other parameters include increased total lung capacity, functional residual capacity and residual volume, which can help distinguish chronic obstructive pulmonary disease (COPD) from restrictive pulmonary disease where these values are lower than normal. Along with these, other tests are decreased vital capacity; and decreased diffusing capacity for carbon monoxide (DLCO). DLCO is non-specific and can be low in other disorders that affect the pulmonary vascular bed, such as interstitial lung disease. DLCO is however useful to distinguish COPD from asthma, in which DLCO is normal or elevated.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 42
Incorrect
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Bloody discharge from the nipple of a 40-year old woman with no obvious lump or abnormality on mammography is suggestive of:
Your Answer: Mastitis
Correct Answer: Intraductal papilloma
Explanation:A small benign tumour, namely intraductal papilloma is most common in women between 35-55 years of age. It is also the commonest cause of spontaneous discharge from a single duct. A lump below the nipple may be sometimes palpable. Ultrasound and ductography are useful investigations., along with cytology of discharge to assess the presence of malignant cells. Confirmation is by breast biopsy.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 43
Incorrect
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Which statement is true regarding the diaphragmatic openings:
Your Answer: The left phrenic nerve passes through the opening at T8
Correct Answer: The thoracic duct passes through the opening at T12
Explanation:The diaphragmatic openings are:
T8 – opening for the inferior vena cavaand the right phrenic nerve
T10 – opening for the oesophagusand the left gastric artery and vein
T12 – opening for the aorta, the thoracic duct and azygos vein.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 44
Incorrect
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A surgeon trainee is assisting in an operation to ligate the ductus arteriosus. The consultant supervising explains that caution is required when placing a clamp on the ductus to avoid injury to an important structure immediately dorsal to it. To which structure is the consultant referring?
Your Answer: Left phrenic nerve
Correct Answer: Left recurrent laryngeal nerve
Explanation:The left recurrent laryngeal nerve branches off the vagus and wraps around the aorta, posterior to the ductus arteriosus/ligamentum arteriosum from whence it courses superiorly to innervate the laryngeal muscles.
Accessory Hemiazygous vein is on the left side of the body draining the posterolateral chest wall and emptying blood into the azygos vein.
The left internal thoracic artery is branch of the left subclavian artery supplying blood to the anterior wall of the thorax.
Left phrenic nerve is lateral to the vagus nerve.
Thoracic duct: is behind the oesophagus, coursing between the aorta and the azygos vein in the posterior chest.
Right recurrent laryngeal nerve: loops around the right subclavian artery and is not in danger in this procedure.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 45
Incorrect
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The thyrocervical trunk branches into which artery that passes upward and in front of the vertebral artery and longus colli muscle:
Your Answer: Internal thoracic
Correct Answer: Inferior thyroid
Explanation:The inferior thyroid artery is an artery in the neck. It arises from the thyrocervical trunk and passes upward, in front of the vertebral artery and longus colli muscle.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 46
Incorrect
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A 33-year old lady presented to the gynaecology clinic with amenorrhoea for 6 months and a recent-onset of milk discharge from her breasts. She was not pregnant or on any medication. On enquiry, she admitted to having frequent headaches the last 4 months. Which of the following findings would you expect to see in her condition?
Your Answer: Hyponatraemia
Correct Answer: Hyperprolactinaemia
Explanation:Excessively high levels of prolactin in the blood is called hyperprolactinaemia. Normally, prolactin levels are less than 580 mIU/l in females and less than 450 mIU/l in men. The biologically inactive macroprolactin can lead to a false high reading. However, the patient remains asymptomatic. Dopamine down-regulates prolactin whereas oestrogen upregulates it. Hyperprolactinaemia can be caused due to lack of inhibition (compression of pituitary stalk or low dopamine levels), or increased production due to a pituitary adenoma (prolactinoma). Either of these causes can lead to a prolactin level of 1000-5000 mIU/l. However, levels more than 5000mIU/l are usually associated due to an adenoma and >100,000 mIU/l are seen in macroadenomas (tumours < 1cm in diameter). Increased prolactin causes increased dopamine release from the arcuate nucleus of hypothalamus. This increased dopamine in turn, inhibits the GnRH (Gonadotrophin Releasing Hormone) thus blocking gonadal steroidogenesis resulting in the symptoms of hyperprolactinaemia. In women, it includes hypoestrogenism, anovulatory infertility, decreased or irregular menstruation or complete amenorrhoea. It can even cause production of breast milk, loss of libido, vaginal dryness and osteoporosis. In men, the symptoms include impotence, decreased libido, erectile dysfunction and infertility. In men, treatment can be delayed due to late diagnosis as they have no reliable indicator such as menstruation that might indicate a problem. Most of the male patients seek help only when headaches and visual defects start to surface.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 47
Incorrect
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In multiple myeloma, which of these cell types confirms the diagnosis when found in a smear of bone marrow aspirate?
Your Answer: Giant cells
Correct Answer: Plasma cells
Explanation:A bone marrow aspiration is the diagnostic test for multiple myeloma, which is a malignant bone tumour that usually affects older adults. The smear reveals clusters of plasma cells, while X-rays tend to show circumscribed lytic lesions or diffuse demineralisation.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 48
Incorrect
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What intrinsic muscle of the larynx is responsible for the tensing of the vocal cords?
Your Answer: Transverse arytenoid
Correct Answer: Cricothyroid muscle
Explanation:The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage. Its action tilts the thyroid forward to help tense the vocal cords.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 49
Incorrect
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How are amino acids transported across the luminal surface of the small intestinal epithelium?
Your Answer: Primary active transport
Correct Answer: Co-transport with sodium ions
Explanation:Once complex peptides are broken down into amino acids by the peptidases present in the brush border of small intestine, they are ready for absorption by at least four sodium-dependent amino acid co-transporters – one each for acidic, basic, neutral and amino acids, present on the luminal plasma membrane. These transporters first bind sodium and can then bind the amino acids. Thus, amino acid absorption is totally dependent on the electrochemical gradient of sodium across the epithelium. The basolateral membrane in contrast, possesses additional transporters to carry amino acids from the cell into the blood, but these are sodium-independent.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 50
Incorrect
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Which ectopic tissue is usually contained in the Meckel's diverticulum?
Your Answer: Hepatic
Correct Answer: Gastric
Explanation:The Meckel’s diverticulum is a vestigial remnant of the omphalomesenteric duct. This structure is also referred to as the vitelline and contains two types of ectopic tissue, namely; gastric and pancreatic.
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This question is part of the following fields:
- Anatomy
- Embryology
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