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Question 1
Correct
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A 56-year-old woman weighs 75 kg. In this patient, total body water, intracellular fluid and extracellular fluid are respectively:
Your Answer: 45 l, 30 l, 15 l
Explanation:The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. The total body water (TBW) content of humans is approximately 60% of body weight. Two-thirds is located in the intracellular and one-third in the extracellular compartment. So, in a 75-kg individual, TBW = 60 Ă— 75/100 = 45 l. Intracellular content = 2/3 Ă— 45 = 30 l and extracellular content = 1/3 Ă— 45 = 15 l.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 2
Incorrect
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A patient who has used NSAIDS for many years presents to the A&E with symptoms of acute haemorrhagic shock. An emergency endoscopy is done that shows that a duodenal ulcer has perforated the posterior wall of the first part of the duodenum. Which artery is most likely to be the cause of the haemorrhage?
Your Answer: Right gastroepiploic
Correct Answer: Gastroduodenal
Explanation:The gastroduodenal artery is a branch of the hepatic artery and descends near the pylorus between the first part of the duodenum and the neck of the pancreas to divide at the lower border of the duodenum into the right gastroepiploic and pancreaticoduodenal arteries. Before it divides, it gives off a few branches to the pyloric end of the stomach and to the pancreas. The artery that is most likely involved in this situation is the gastroduodenal artery since it is posterior to the first part of the duodenum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 3
Correct
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During work up for a 29 year-old lady who complained of chest pain, a computed tomography showed a large mass in the posterior mediastinum. Which among the following structures could be involved?
Your Answer: Lymph nodes
Explanation:Boundaries of the posterior mediastinum include:
Superior: a plane through the sternal angle and T4/5
Inferior: the diaphragm
Anterior: the middle mediastinal structures
Posterior the spinal cord.
Structures in the posterior mediastinum include the descending thoracic aorta, the azygos system, oesophagus, thoracic duct and lymph nodes. The great vessels and structures at the root of the lung are part of the middle mediastinum. In this case, the lymph nodes is the correct answer.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 4
Correct
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A 27 year-old male patient was admitted to the hospital due to recurrent fever for the past 2 weeks. The patient claimed that he is an intravenous drug user. Following work up, the patient was diagnosed with infective endocarditis. Which is the most likely organism responsible for this diagnosis?
Your Answer: Staphylococcus aureus
Explanation:Acute bacterial endocarditis is a fulminant illness lasting over days to weeks (<2weeks). It is most likely due to Staphylococcus aureus especially in intravenous drug abusers.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 5
Incorrect
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An experiment was conducted in which the skeletal muscle protein (not smooth muscle) involved in contraction was selectively inhibited. Which protein was inhibited?
Your Answer: Actin
Correct Answer: Troponin
Explanation:The mechanism of contraction of smooth muscles is different from that of skeletal muscles in which the contractile protein is troponin whilst in smooth muscle contraction is a protein called calmodulin. Calmodulin reacts with calcium ions and stimulates the formation of myosin crossbridges.
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This question is part of the following fields:
- General
- Physiology
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Question 6
Correct
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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: 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 7
Incorrect
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What is the 5-year survival rate of carcinoma of the pancreas?
Your Answer: 15 per cent
Correct Answer: 30 per cent
Explanation:Pancreatic cancer typically has a poor prognosis, partly because the cancer usually initially remains symptomless, leading to locally advanced or metastatic disease at the time of diagnosis. Median survival from diagnosis is around 3–6 months. Even in those suitable for resectional surgery, 5-year survival rates are still only 30 per cent.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 8
Correct
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The surgical registrar is doing an exploratory laparotomy on a 35 year old lady of African descent with tuberculous of the abdomen and suspected perforation. The small bowel is matted due to adhesions and it is difficult to differentiate the ileum from the jejunum. Which of the following features is typical of the jejunum?
Your Answer: It has sparse aggregated lymph nodules
Explanation:The jejunum has a wider diameter, is thicker and more vascularized, hence of a deeper colour compared to the ileum. The valvulae conniventes (circular folds) of its mucous membranes are large and thick and its villi are larger than those in the ileum. The jejunum also has sparse aggregates of lymph nodules and most of its part occupies the umbilical and left iliac regions whilst the ileum is mostly in the umbilical, hypogastric, right iliac and pelvic regions.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 9
Correct
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A 32-year-old man presented with a metabolic acidosis and increased anion gap. What is the most likely cause of the changes of the anion gap in this patient?
Your Answer: Lactic acidosis
Explanation:High anion gap in metabolic acidosis is caused generally by the elevation of the levels of acids like ketones, lactate, sulphates in the body, which consume the bicarbonate ions. Other causes of a high anion gap include overdosing on salicylates, uraemia, rhabdomyolysis, hypocalcaemia, hypomagnesaemia, or ingestion of toxins such as ethylene glycol, methanol, propyl alcohol, cyanide and iron.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 10
Correct
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Which of the following abnormalities can be seen in patients with hypermagnesemia?
Your Answer: Respiratory depression
Explanation:Hypermagnesemia is an electrolyte disturbance in which there is a high level of magnesium in the blood. It is defined as a level greater than 1.1 mmol/L. Symptoms include weakness, confusion, decreased breathing rate, and cardiac arrest.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 11
Correct
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Increased resistance to flow of blood in cerebral vessels is most likely seen in:
Your Answer: Elevation in systemic arterial pressure from 100 to 130 mmHg
Explanation:Constant cerebral blood flow is maintained by autoregulation in the brain, which causes an increase in local vascular resistance to offset an increase in blood pressure. There will be an increase in cerebral blood flow (and decrease in resistance to cerebral blood flow) with a decrease in arterial oxygen or an increase in arterial CO2. Similarly, a decrease in viscosity will also increase the blood flow. Due to increased brain metabolism and activity during a seizure, there will also be an increase in the cerebral blood flow.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 12
Incorrect
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Which of the following factors will not affect the wound healing process in a young women who suffered serious burns to her chest and hands?
Your Answer: Zinc
Correct Answer: Vitamin A deficiency
Explanation:Healing can be sped-up or slowed down due to various reasons: 1. blood supply, 2. infection, 3. denervation, 4. collection of blood/hematoma, 5. mechanical stress, 6. foreign body, 7. techniques used during surgery and 8. dressing of the wound. Other systemic factors include 1. nutrition e.g. deficiency of zinc, vitamin C, protein deficiency, 2. metabolic status, 3. circulatory status and 4. hormonal influence
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 13
Correct
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Which of the following clinical signs will be demonstrated in a case of Brown-SĂ©quard syndrome due to hemisection of the spinal cord at mid-thoracic level?
Your Answer: Ipsilateral spastic paralysis, ipsilateral loss of vibration and proprioception (position sense) and contralateral loss of pain and temperature sensation beginning one or two segments below the lesion
Explanation:Brown–Séquard syndrome results due to lateral hemisection of the spinal cord and results in a loss of motricity (paralysis and ataxia) and sensation. The hemisection of the cord results in a lesion of each of the three main neural systems: the principal upper motor neurone pathway of the corticospinal tract, one or both dorsal columns and the spinothalamic tract. As a result of the injury to these three main brain pathways the patient will present with three lesions. The corticospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the upper motor neurons). The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense). The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion. At the lesion site, all sensory modalities are lost on the same side, and an ipsilateral flaccid paralysis.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 14
Correct
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A 13 year old girl presented with signs of shortness of breath, chest pain, non-productive cough, oedema of the lower extremities and cyanosis of the fingertips. She has a history of a ventricular septal defect not surgically corrected. The most probable cause of these symptoms is:
Your Answer: Shunt reversal
Explanation:A ventricular septal defect (VSD) is a common form of congenital heart defects and is characterised by the presence of a hole in the wall that separates the right from the left ventricle. Medium or large defects can cause many complications. One of these complication is Eisenmenger syndrome, characterised by reversal of the shunt (from left-to-right shunt into a right-to-left) ,cyanosis and pulmonary hypertension.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 15
Correct
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During a procedure in the mediastinum, the surgeon accidentally injured a key structure that lies immediately anterior to the thoracic duct. Which structure is likely to be injured?
Your Answer: Oesophagus
Explanation:In the mid-thorax, the azygos vein, thoracic duct and aorta (in this order from right to the left) are all located posterior to the oesophagus. The superior vena cava, left internal jugular vein and trachea are not found in the mid thorax.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 16
Correct
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Inside the palatoglossal arch is a muscle. Which nerve innervates this muscle?
Your Answer: X
Explanation:The palatoglossal arch contains the palatoglossal muscle which is innervated by the vagus nerve which is the tenth cranial nerve. So the correct answer is X
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 17
Correct
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After being admitted to the hospital, a 60-year-old man is administered sodium nitroprusside. Which class of drugs does nitroprusside belong to?
Your Answer: Vasodilators
Explanation:Sodium nitroprusside is a potent peripheral vasodilator that affects both arterioles and venules. It is often administered intravenously to patients who are experiencing a hypertensive emergency. It reduces both total peripheral resistance as well as venous return, so decreasing both preload and afterload. For this reason it can be used in severe cardiogenic heart failure where this combination of effects can act to increase cardiac output. It is administered by intravenous infusion. Onset is typically immediate and effects last for up to ten minutes. The duration of treatment should not exceed 72 hours.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 18
Incorrect
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A 58-year-old woman has had a headache, fever, lethargy and nausea for the last 10 days. He undergoes a CT scan which reveals a lesion in his frontal lobe, which, after a biopsy, is found to be formed by granulation tissue with collagenisation, gliosis and oedema. What's the most likely diagnosis?
Your Answer: Glioblastoma
Correct Answer: Chronic brain abscess
Explanation:A cerebral abscess can result from direct extension of cranial infections, penetrating head trauma, haematogenous spread, or for unknown causes. An abscess forms when an area of cerebral inflammation becomes necrotic and encapsulated by glial cells and fibroblasts. Oedema around the abscess can increase the intracranial pressure. Symptoms result from increased intracranial pressure and mass effects. In a CT scan, an abscess appears as an oedematous mass with ring enhancement.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 19
Correct
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Which of the following structures lying posterior to the ovary are at risk of injury in excision of a malignant tumour in the right ovary?
Your Answer: Ureter
Explanation:The ovaries are two nodular structures situated one on either side of the uterus in relation to the lateral wall of the pelvis and attached to the back of the broad ligament of the uterus, lying posteroinferiorly to the fallopian tubes. Each ovary has a lateral and medial surface. The ureter is at greater risk of iatrogenic injury at this location.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 20
Incorrect
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Following a lacerating injury along the anterior border of the trapezius muscle in the neck, a man has the point of his shoulder (scapula) sagging and he has difficulty with full abduction of his arm. Which nerve is most likely injured?
Your Answer: Suprascapular
Correct Answer: Accessory (cranial nerve XI)
Explanation:Injury to the accessory nerve denervates the trapezius muscle so that the person will no longer be able to raise the acromion of the shoulder. The dorsal scapular nerve supplies the rhomboids i.e. major and minor and the levator scapulae so that injury to this nerve weakens retraction of the scapula. The greater occipital nerve is responsible for sensation of the posterior scalp. The axillary nerve innervates the deltoid muscle which is responsible for abduction of the arm and the suprascapular nerve is responsible for rotating the humerus laterally. Cutaneous nerves supply the skin.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 21
Correct
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A 30-year old lady was admitted to the general surgical ward after a diagnosis of perforation of the first part of the duodenum that resulted from a long standing ulcer. If this perforation led to the expulsion of the gastric content that resulted to the erosion of an artery found in this part of the duodenum (the posterior of the first part of the duodenum). Which of the following arteries is this most likely to be?
Your Answer: Gastroduodenal
Explanation:The proximal part of the duodenum is supplied by the gastroduodenal artery. This artery is found descending behind the first part of the duodenum after branching from the hepatic artery. If gastric content was to be expelled in the posterior portion of the first part of the duodenum, then this artery would be most likely to be damaged. The common hepatic artery and the left gastric artery are branches of the coeliac trunk that are found superior to the duodenum. The proper hepatic artery is a branch of the common hepatic artery also found superior to the duodenum. The superior mesenteric artery is found behind the pancreas as a branch of the aorta that is at the bottom of the L1 level. The right gastric artery arises above the pylorus from the proper hepatic artery and supplies the lesser curvature of the stomach. The intestinal arteries supply the ileum and the jejunum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 22
Incorrect
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A patient is suspected to have Blastomyces dermatidis infection. The patient contracted the disease most likely through which port of entry?
Your Answer: Skin
Correct Answer: Respiratory tract
Explanation:Blastomycosis disease is a fungal infection acquired through inhalation of the spores. It caused by the organism Blastomyces dermatitidis and manifests as a primary lung infection in about 70% of cases. The onset is relatively slow and symptoms are suggestive of pneumonia.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 23
Incorrect
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A medical student is asked to calculate the net pressure difference in a capillary wall, considering: Interstitial fluid hydrostatic pressure = –3 mmHg, Plasma colloid osmotic pressure = 28 mmHg, Capillary hydrostatic pressure = 17 mmHg, Interstitial fluid colloid osmotic pressure = 8 mmHg, and Filtration coefficient = 1. Which is the correct answer?
Your Answer: +3 mmHg
Correct Answer: 0 mmHg
Explanation:The rate of filtration at any point along a capillary depends on a balance of forces sometimes called Starling’s forces after the physiologist who first described their operation in detail. The Starling principle of fluid exchange is key to understanding how plasma fluid (solvent) within the bloodstream (intravascular fluid) moves to the space outside the bloodstream (extravascular space). Fluid movement = k[(pc– pi)–(Πc– Πi)] where k = capillary filtration coefficient, pc = capillary hydrostatic pressure, pi= interstitial hydrostatic pressure, Πc = capillary colloid osmotic pressure, Πi = interstitial colloid osmotic pressure. Therefore: 1 × [capillary hydrostatic pressure (17) – interstitial fluid hydrostatic pressure (–3)] – [plasma colloid osmotic pressure (28) – interstitial fluid colloid osmotic pressure (8)] = 0 mmHg
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 24
Correct
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Which of these structures is most likely to be damaged if a patient loses consciousness days or weeks after an otherwise insignificant head trauma, especially in elderly patients?
Your Answer: Dural bridging vein
Explanation:A subdural haematoma is a type of hematoma, usually associated with traumatic brain injury, in which blood collects between the dura mater and the pia-arachnoid mater. Symptoms of subdural haemorrhage have a slower onset than those of epidural haemorrhages because the lower pressure veins bleed more slowly than arteries. These injuries are more common in elderly patients, especially those taking antiplatelet or anticoagulant drugs. Oedema and increased intracranial pressure are unusual.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 25
Correct
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A 20-year old boy presented with low grade fever, night sweats and weakness over two months. On examination, he had multiple, non-tender, cervical, supraclavicular and axillary adenopathy. Microscopy of lymph node biopsy showed the presence of Reed-Sternberg cells. He is likely suffering from:
Your Answer: Hodgkin’s lymphoma
Explanation:Hodgkin’s lymphoma is a disease characterized by malignant proliferation of cells of the lymphoreticular system. It can be localized or disseminated, and can involve the nodes, spleen, liver and marrow. Symptoms of the disease include non-tender lymphadenopathy, fever, night sweats, weight loss, itching and hepatosplenomegaly. Histologically, the involved nodes show the presence of Reed-Sternberg cells, which are large, binucleated cells, in a heterogenous cellular infiltrate of histiocytes, lymphocytes, monocytes, plasma cells and eosinophils.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 26
Correct
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What is the pH of freshly formed saliva at ultimate stimulation?
Your Answer: 8
Explanation:Saliva has four major components: mucus (lubricant), α-amylase (enzyme that initiates digestion of starch), lingual lipase (enzyme that begins fat digestion), and a slightly alkaline electrolyte solution for moistening food. As the secretion rate of saliva increases, its osmolality increases. Moreover, the pH changes from slightly acidic (at rest) to basic (pH 8) at ultimate stimulation. This occurs due to increase of HCO3-. Amylase and mucus also increase in concentration after stimulation.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 27
Correct
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In which situation is a stretch reflex such as knee jerk likely to be exaggerated?
Your 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 cell is classified on the basis of its regenerative ability. Which of the following cells represent a permanent cell?
Your Answer: Acinar cell of the pancreas
Correct Answer: Erythrocyte
Explanation:An erythrocyte is the last cell in the progeny of RBC cell division and is not capable of further division and regeneration. Hepatocytes, osteocytes and epithelium of kidney tubules are all stable cells. Colonic mucosa and pluripotent hematopoietic stem cells are all labile cells.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 29
Correct
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A 40-year old gentleman underwent a computed tomographic scan for the abdomen to rule out blunt abdominal trauma, after a vehicular accident. The scan revealed no abnormal finding except for a 1 cm-sized cortical mass in the left adrenal gland. The doctor-on-call decided to not intervene for this mass because it was likely to be a:
Your Answer: Non-functioning adrenal adenoma
Explanation:Adrenal adenomas are common, benign lesions which are asymptomatic and seen in 10% of population. Usually detected incidentally on Computed tomography (‘incidentaloma’), only around 1 in 10,000 are malignant (adenocarcinoma). Adrenal adenomas rarely need to be investigated, especially if they are homogenous and less than 3 cm in diameter. Follow-up imaging can be done after an interval of 3-6 months to assess any change in size. Some adenomas can secrete cortisol (leading to Cushing syndrome), or aldosterone (leads to Conn syndrome) or androgens (leading to hyperandrogenism).
Haematomas and simple cysts are not usually seen in adrenal gland. Infection due to Histoplasma capsulatum is usually bilateral and leads to multiple granulomas. Adrenal metastasis will usually demonstrate a lung primary and the adrenal lesions will be often multiple and larger than 1 cm.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 30
Correct
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A 78-year-old man who has been bedridden for a month is prescribed griseofulvin. What class of drugs does griseofulvin belong to?
Your Answer: Antifungal
Explanation:Griseofulvin is an antifungal drug. It is administered orally, and it is used to treat ringworm infections of the skin and nails. It binds to keratin in keratin precursor cells and makes them resistant to fungal infections. Griseofulvin works by interfering with fungal mitosis.
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This question is part of the following fields:
- Pathology
- Pharmacology
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SESSION STATS - PERFORMANCE PER SPECIALTY
