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Question 1
Correct
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In a hypertensive patient with secondary hyperaldosteronism, aldosterone is released mainly in response to:
Your Answer: Angiotensin II
Explanation:Secondary hyperaldosteronism in hypertension is either due to primary renin overproduction by the kidneys or renin overproduction secondary to decreased renal blood flow. The main stimulus for aldosterone release are adrenocorticotrophic hormone (ACTH), angiotensin II and high plasma K+ levels. Low plasma Na+ might also stimulate the adrenal cortex. Fluid overload will reduce aldosterone secretion. Atrial natriuretic peptide is secreted under conditions of expanded extracellular volume and will not lead to aldosterone secretion.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 2
Correct
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A patient sustained an iatrogenic injury to one of the structures passing through the deep inguinal ring. This was during an operation to repair an inguinal hernia. Which structure is most likely to be injured?
Your Answer: Round ligament of the uterus
Explanation:The deep inguinal ring transmits the spermatic cord in the man and the round ligament of the uterus in the female. It is bound below and medially by the inferior epigastric vessels (so these don’t go through it).
The ilioinguinal nerve, although it courses through the inguinal canal, does not pass through it.
The iliohypogastric nerves run between the internal oblique and transversus abdominis in the abdominal wall, piercing the internal oblique at the anterior superior iliac spine to travel just deep to the external oblique.
The inferior epigastric artery runs between the transversus abdominis and the peritoneum forming the lateral umbilical fold.
The medial umbilical ligament is the obliterated umbilical artery that it lies within the medial umbilical fold of peritoneum. -
This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 3
Correct
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In a cardiac cycle, what event does the opening of the atrioventricular (AV) valves coincide with?
Your Answer: Beginning of diastole
Explanation:Cardiac diastole refers to the time period when the heart is relaxed after contraction and is preparing to refill with blood. Both ventricular and atrial diastole are together known as complete cardiac diastole. At its beginning, the ventricles relax, causing a drop in the ventricular pressure. As soon as the left ventricular pressure drops below that in left atrium, the mitral valve opens and there is ventricular filling of blood. Similarly, the tricuspid valve opens filling the right atrium.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 4
Correct
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Which of these is secreted by both macrophages and muscle cells?
Your Answer: Interleukin-6
Explanation:IL-6 is secreted by the T cells and macrophages and is a pro inflammatory cytokine. It is secreted in response to trauma e.g. burns and tissue damage that leads to inflammation. Apart from this its is also a myokine and is elevated due to muscle contraction. Other functions include: stimulate osteoclast formation when secreted by osteoblasts, mediate fever in acute phase response and are responsible for energy metabolism in muscle and fatty tissues. Inhibitors of IL-6 e.g. oestrogen are used as a treatment for postmenopausal osteoporosis.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 5
Incorrect
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A 37 year old woman has recently undergone a mastectomy along with axillary node clearance for an invasive ductal carcinoma. Histological analysis show a completely excised grade III lesion measuring 3.5cm. Two of the axillary nodes are significant for metastatic spread. The tumour is found to be oestrogen receptor negative. Which of the following would be the next best step in the management of this patient?
Your Answer: Surveillance alone
Correct Answer: Administration of cytotoxic chemotherapy
Explanation:Chemotherapy is offered to patients to help downstage advanced lesions to facilitate breast conserving surgery i.e. in grade 3 tumours with axillary node metastasis.
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This question is part of the following fields:
- Breast And Endocrine Surgery
- Generic Surgical Topics
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Question 6
Correct
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A 26-year-old female sought consultation due to excessive vaginal discharge. Vaginal smear showed numerous bacilli under the microscope. The organism was non-pathogenic. What is the most likely organism:
Your Answer: Lactobacillus species
Explanation:Lactobacillus is a Gram-positive facultative bacteria. It is commonly present in the vagina and the gastrointestinal tract. Colonization of Lactobacillus is usually benign and it makes up a small portion of the gastrointestinal flora.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 7
Correct
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A 38 year old teacher presents with a mass lesion in her left breast. A biopsy and imaging confirmed a 2.5cm lesion in the upper inner quadrant of her left breast and a 1.5cm lesion at the central aspect of the same breast. Examination of her axilla revealed lymphadenopathy and a fine needle aspirate from the node showed malignant cells. Which of the following would be the best course of action?
Your Answer: Simple mastectomy and axillary node clearance
Explanation:Indications for a simple mastectomy with a concomitant axillary procedure, which may be either a sentinel node biopsy or an axillary clearance, are as follows:
– Locally advanced breast cancer
– Multifocal breast cancer
– Large tumour relative to the size of the breast, excision of which may compromise final cosmesis
– Extensive ductal carcinoma in situ (DCIS)Multifocality and multicentricity (MFMC) are frequently used descriptors to assess the extent of disease in patients presenting breast cancer. The presence of two or more foci of cancer within the same breast quadrant is defined as multifocal, while the presence of two or more foci of cancer in different quadrants of the same breast is defined as multicentric. A simple mastectomy involves removing the breast along with an ellipse of skin that encompasses the nipple-areola complex. Unlike a radical mastectomy, it does not involve removal of the underlying muscles and uninvolved lymph nodes.
Patient unsuitability for breast-conserving approaches as a result of contraindications for radiation therapy – Such contraindications include a previous history of chest wall irradiation, either after previous breast-conserving therapy or in mantle field radiation therapy for lymphoma; severe skin disorders, such as scleroderma and psoriasis; and severe pulmonary dysfunction
Patient preference for mastectomy – A patient who is a suitable candidate for breast conservation may opt for a mastectomy instead.
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This question is part of the following fields:
- Breast And Endocrine Surgery
- Generic Surgical Topics
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Question 8
Correct
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An 11 month old baby boy is taken to the clinic with a history of a right groin swelling. A photograph on the father's mobile phone, shows what looks like an inguinal hernia. What is the most appropriate course of action?
Your Answer: Undertake an open inguinal herniotomy
Explanation:Answer: Undertake an open inguinal herniotomy
Inguinal hernia is a type of ventral hernia that occurs when an intra-abdominal structure, such as bowel or omentum, protrudes through a defect in the abdominal wall. Inguinal hernias do not spontaneously heal and must be surgically repaired because of the ever-present risk of incarceration. Generally, a surgical consultation should be made at the time of diagnosis, and repair (on an elective basis) should be performed very soon after the diagnosis is confirmed.
The infant or child with an inguinal hernia generally presents with an obvious bulge at the internal or external ring or within the scrotum. The parents typically provide the history of a visible swelling or bulge, commonly intermittent, in the inguinoscrotal region in boys and inguinolabial region in girls. The swelling may or may not be associated with any pain or discomfort.
Open herniotomy is its standard treatment against which all alternative modalities of treatment are evaluated. It is credited with being easy to perform, having a high success rate, and low rate of complications.
The use of prosthetic mesh in these patients is rare, however not uncalled for. Laparoscopic inguinal herniotomy is significantly associated with longer operative time for unilateral cases and a reduction in metachronous hernia development when compared to open inguinal herniotomy. There was a trend towards higher recurrence rate for laparoscopic repairs and shorter operative time for bilateral cases. A well conducted randomized controlled trial is warranted to compare both approaches. -
This question is part of the following fields:
- Generic Surgical Topics
- The Abdomen
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Question 9
Incorrect
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A 7-month-old abandoned baby with congenital non-communicating hydrocephalus is hosted by a clinic at its new-born hostel. A CT scan of the baby's brain reveals what might be a blockage of the ventricular system between the third and the fourth ventricles. Which of the following is the most likely blocked structure?
Your Answer: Central canal
Correct Answer: Cerebral aqueduct
Explanation:The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 10
Incorrect
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Which of the following cytokines produced by the T cell induce MHC-II proteins?
Your Answer: Interleukin-1
Correct Answer: γ-Interferon
Explanation:Interferons elicit a non-specific antiviral activity by inducing specific RNA synthesis and expression of proteins in neighbouring cells. Common interferon inducers are viruses, double-stranded RNA and micro-organisms. INF-γ is produced mainly by CD4+, CD8+ T cells and less commonly by B cells and natural killer cells. INF-γ has antiviral and antiparasitic activity but its main biological activity appears to be immunomodulatory. Among its many functions are activation of macrophages and enhanced expression of MHC-II proteins or macrophages.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 11
Correct
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Which of the following key features will be seen in an organ undergoing atrophy?
Your Answer: A greater number of autophagic vacuoles
Explanation:Atrophy is characterised by the breakdown of intracellular components along with organelles and packing them into vacuoles known as autophagic vacuoles. This is an adaptive response that separates the damaged cellular structures from the rest of the cells.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 12
Correct
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What is the normal glomerular filtration rate?
Your Answer: 125 mL/min
Explanation:The normal glomerular filtration rate (GFR) in humans is 125 mL/min. After the age of 40, GFR decreases progressively by about 0.4–1.2 mL/min per year.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 13
Correct
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Which of the following statements is true of Colles’ fracture?
Your Answer: Is a cause of carpal tunnel syndrome
Explanation:Colles’ fracture is a distal fracture of the radius that is a known cause of carpal tunnel syndrome (compression of the median nerve in the carpal tunnel). It rarely results in ulnar nerve compression. A Colles’ fracture is extra-articular and does not extend into the wrist joint, otherwise this would make it an intra-articular fracture (Barton’s fracture). The distal fragment in a Colles’ fracture is displaced dorsally, unlike in a Smith’s fracture where the distal fragment is displaced volarly (ventrally). Associated fracture of the ulnar styloid process may occur and is a common associated injury.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 14
Correct
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A 55-year-old cleaner is admitted after a fall. She is haemodynamically unstable and a CT has shown a massive retroperitoneal haematoma. She is on warfarin. What is the most appropriate course of action?
Your Answer: Infusion of human prothrombin complex and vitamin K
Explanation:Active, serious haemorrhage due to Warfarin should be treated with four-factor prothrombin complex concentrate (PCC), if available.
While costly, an essential advantage FFP confers to emergency care is that, in contrast to FFP, it results in a more rapid reversal of coagulopathy and does not require thawing or blood group typing. Additionally, it has a reduced risk of volume overload, transfusion-related acute lung injury, transfusion reactions, and infectious disease transmission. Despite these advantages, no mortality benefit has been proven for PCC compared with FFP.
Alternatively, recombinant factor VIIa (rFVIIa) has been reported to be effective in rapidly lowering INR due to warfarin toxicity and may be considered if PCC is not available. FFP is effective at lowering the INR and was historically first-line therapy for warfarin toxicity with serious or life-threatening bleeding, although it has now been superseded by PCC, which lowers the INR more rapidly. If PCC or rFVIIa is not available, 4 units of FFP may be administered instead.
Administer vitamin K1, 10 mg, by slow IV infusion, -
This question is part of the following fields:
- Principles Of Surgery-in-General
- Surgical Technique And Technology
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Question 15
Correct
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A 26-year-old woman who is 18 weeks pregnant presents with sudden chest pain. On examination, her heart rate is 130 bpm, blood pressure is 150/70 mmHg, and saturation is 92% on 15L oxygen. Signs of thrombophlebitis are seen in the left leg. Moreover, auscultation of the heart reveals no murmurs and her chest is clear.What is the most likely diagnosis?
Your Answer: Pulmonary embolism
Explanation:Chest pain, hypoxia, and clear chest on auscultation in pregnancy should lead to a high suspicion of pulmonary embolism (PE).
PE is one of the leading causes of mortality in pregnancy. Evaluation with low-dose perfusion scintigraphy may be preferable to computed tomographic pulmonary angiography (CTPA).
PE is treated with LMWH throughout pregnancy and for 4–6 weeks after childbirth. Warfarin is contraindicated in pregnancy (though may be continued in women with mechanical heart valves due to a significant risk of thromboembolism). -
This question is part of the following fields:
- Emergency Medicine And Management Of Trauma
- Principles Of Surgery-in-General
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Question 16
Correct
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The prostatic plexus of nerves contains nerve fibres that innervate penile tissue allowing for erection. From which of the following nerves do these fibres originate?
Your Answer: Pelvic splanchnics
Explanation:Pelvic splanchnic nerves are examples of the parasympathetic nerves that innervate the smooth muscle and glands of the pelvic viscera. They are also the nerves contributing fibres to the prostatic plexus which innervate penile erectile tissue.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 17
Correct
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A 55 year old man presented with a 4 day history of cough and fever. His sputum culture showed the presence of Strep pneumoniae. Which of the following substances produced by the inflammatory cells will result in effective clearance of this organism from the lung parenchyma?
Your Answer: Hydrogen peroxide
Explanation:Hydrogen peroxide is produced by myeloperoxidase to form a potent oxidant that eliminates bacteria, but is not effective in chronic granulomatous diseases.
Platelet activating factor will lead to the activation, adhesion and aggregation of platelets but will not directly kill bacteria.
Prostaglandins cause vasodilation but do not activate neutrophils.
Kallikrein promotes formation of bradykinin that leads to vasodilation.
Leukreines increase vascular permeability.
Cytokines are communicating molecules between immune cells but directly will not kill bacteria.
Interleukins will regulate the immune response. -
This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 18
Incorrect
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A 19-year-old female presents to the oncology clinic after noticing a painless neck lump. On examination, she is noted to have bilateral thyroid masses and multicentric nodules near the base of the thyroid. Her corrected calcium level is 2.18 mg/dL. Which of the following is the most likely diagnosis?
Your Answer: Follicular thyroid carcinoma
Correct Answer: Medullary carcinoma of the thyroid associated with multiple endocrine neoplasia
Explanation:Based on the aforementioned findings in this case, the most likely diagnosis is medullary carcinoma of the thyroid associated with multiple endocrine neoplasia (MEN).
Medullary thyroid cancer is a tumour of the parafollicular cells (C cells) of the thyroid and is neural crest in origin. It may be familial and occur as part of the MEN 2A disease spectrum. Less than 10% of thyroid cancers are of this type with patients typically presenting as children or young adults. Diarrhoea occurs in 30% of the cases. In association with MEN syndromes, medullary thyroid cancers are always bilateral and multicentric. Spread may either be lymphatic or haematogenous, and as these tumours are not derived primarily from thyroid cells, they are not responsive to radioiodine.
Toxic nodular goitre is very rare. In sporadic medullary carcinoma of the thyroid, patients typically present with a unilateral solitary nodule and it tends to spread early to the lymph nodes in neck.
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This question is part of the following fields:
- Generic Surgical Topics
- Head And Neck Surgery
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Question 19
Correct
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Which of the following can occur even in the absence of brainstem co-ordination?
Your Answer: Gastric emptying
Explanation:Although gastric emptying is under both neural and hormonal control, it does not require brainstem co-ordination. Increased motility of the orad stomach (decreased distensibility) or of the distal stomach (increased peristalsis), decreased pyloric tone, decreased duodenal motility or a combination of these, all increase the rate of gastric emptying. The major control mechanism for gastric emptying is through duodenal gastric feedback. The duodenum has receptors for the presence of acid, carbohydrate, fat and protein digestion products, osmolarity different from that of plasma, and distension. Activating these receptors decreases the rate of gastric emptying. Neural mechanisms involve both enteric and vagal pathways and a vagotomy impairs the gastric emptying regulation. CCK (cholecystokinin) slows gastric emptying at physiological levels of the hormone. Gastrin, secretin and glucose-1-phosphate also slow gastric emptying, but require higher doses.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 20
Correct
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A 52 year old man complains of significant abdominal pain and presents to his family doctor. Past medical history shows that he is recovering following a live donor related renal transplant. Which analgesic drug would be avoided in this patient?
Your Answer: Diclofenac
Explanation:As a class, NSAIDs are known to have direct nephrotoxic effects including afferent vasoconstriction leading to reduced glomerular filtration; allergic reactions leading to tubulointerstitial nephritis; nephrotic syndromes, which commonly include minimal change disease and membranous glomerulonephropathy; fluid and sodium retention; worsening of pre-existing hypertension; papillary necrosis and various electrolyte disturbances, including hyponatremia, hyperkalaemia and type 4 renal tubular acidosis.
The use of NSAIDs should be minimized among patients with Stage 3 CKD and avoided in those with Stage 4 or Stage 5 CKD with residual kidney function or recipients of kidney transplant regardless of CKD stage. It is conceivable that compromised intraglomerular hemodynamic may be potentiated with concurrent use of NSAIDs and calcineurin inhibitors in the transplant setting.
Diclofenac which is an NSAID should therefore be avoided in this patient. -
This question is part of the following fields:
- Generic Surgical Topics
- Organ Transplantation
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Question 21
Correct
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Paracentesis of ascetic fluid in a 45-year old woman revealed the following : clear, yellow fluid with protein 2.0 g/dl and a few mesothelial and mononuclear cells seen. No malignant cells seen. What is the likely diagnosis?
Your Answer: Micronodular cirrhosis
Explanation:Cirrhosis is disease of the liver that is characterized by fibrosis leading to disorganization of the hepatic architecture. It shows the development of regenerative nodules surrounded by dense fibrotic tissue. Cirrhosis shows non-specific symptoms initially, which include fatigue, anorexia and weight loss. It can later progress to portal hypertension, ascites and liver failure.
Micronodular cirrhosis is named so, due to the uniformly small nodules (<3 mm in diameter) and thick regular bands of connective tissue. These nodules lack lobular organization with distortion of central hepatic venules and portal triads. Over a period of time, macronodular cirrhosis develops, with bigger nodules (3 mm to 5 cm in diameter) surrounded by broad fibrous bands, and some amount of lobular organization. Mixed cirrhosis combines features of both micronodular and macronodular cirrhosis. -
This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 22
Correct
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In a young, sexually active male, what is the most common cause of non-gonococcal urethritis?
Your Answer: Chlamydia
Explanation:Non-gonococcal urethritis is most commonly caused by Chlamydia trachomatis (50% cases). Less common organisms include Mycoplasma genitalium, Urea urealyticum and Trichomonas vaginalis. Chlamydia is also the commonest cause of non-gonococcal cervicitis in women and proctitis in both sexes.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 23
Correct
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A 65-year-old man complains of headaches, weakness, cramps, and confusion; blood tests reveal he has severe hyponatremia. The most likely cause is:
Your Answer: Severe diarrhoea or vomiting
Explanation:Hyponatraemia occurs when the sodium level in the plasma falls below 135 mmol/l. Hyponatraemia is an abnormality that can occur in isolation or, more commonly as a complication of other medical illnesses. Severe hyponatraemia may cause osmotic shift of water from the plasma into the brain cells. Typical symptoms include nausea, vomiting, headache and malaise. As the hyponatraemia worsens, confusion, diminished reflexes, convulsions, stupor or coma may occur. The cause of hyponatremia is typically classified by a person’s fluid status into low volume, normal volume, and high volume. Low volume hyponatremia can occur from diarrhoea, vomiting, diuretics, and sweating.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 24
Correct
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A 40-year old woman presents with tightening of the skin over her fingers which makes movement of her fingers difficult.. She also gives a history of her fingers turning blue on exposure to low temperatures. She admits to gradual weight loss. Investigations reveal negative rheumatoid factor, negative antinuclear antibody and a positive anticentromere body. Which of the following conditions is she likely to have?
Your Answer: Oesophageal stricture
Explanation:Scleroderma is a connective tissue disorder that ranges in severity and progression. The disease could show generalised skin thickening with rapid, fatal, visceral involvement; or only cutaneous involvement (typically fingers and face). The slow progressive form is also known as ‘limited cutaneous scleroderma’ or CREST syndrome (calcinosis cutis, Raynaud’s phenomenon, (o)oesophageal dysmotility, sclerodactyly, and telangiectasia).
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 25
Correct
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A 40 year old female presents to her family doctor with a goitre. On examination, the goitre feels 'lumpy'. Blood tests done show a TSH of 12 and a free T4 of 2 and her antithyroid peroxidase antibodies are high. Which of the following is the most likely cause?
Your Answer: Hashimoto's
Explanation:Hashimoto thyroiditis is part of the spectrum of autoimmune thyroid diseases (AITDs) and is characterized by the destruction of thyroid cells by various cell- and antibody-mediated immune processes.
The thyroid gland may become firm, large, and lobulated in Hashimoto’s thyroiditis, but changes in the thyroid can also be nonpalpable. Enlargement of the thyroid is due to lymphocytic infiltration and fibrosis, rather than tissue hypertrophy.Laboratory studies and potential results for patients with suspected Hashimoto thyroiditis include the following:
– Serum thyroid-stimulating hormone (TSH) levels: Sensitive test of thyroid function; levels are invariably raised in hypothyroidism due to Hashimoto thyroiditis and in primary hypothyroidism from any cause
– Free T4 levels: Needed to correctly interpret the TSH in some clinical settings; low total T4 or free T4 level in the presence of an elevated TSH level further confirms diagnosis of primary hypothyroidism
– T3 levels: Low T3 level and high reverse T3 level may aid in the diagnosis of nonthyroidal illnessThyroid autoantibodies: Presence of typically anti-TPO (anti-thyroid peroxidase) and anti-Tg (anti-thyroglobulin) antibodies delineates the cause of hypothyroidism as Hashimoto thyroiditis or its variant; however, 10-15% of patients with Hashimoto thyroiditis may be antibody negative.
While their role in the initial destruction of the follicles is unclear, antibodies against thyroid peroxidase (TPO) (also called TPOAb) or thyroglobulin are relevant, as they serve as markers for detecting the disease and its severity. They are hypothesized to be the secondary products of the T cell mediated destruction of the gland. -
This question is part of the following fields:
- Breast And Endocrine Surgery
- Generic Surgical Topics
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Question 26
Correct
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Loperamide is a drug used to treat diarrhoea. What is the mechanism of action of loperamide?
Your Answer: Opiate agonist
Explanation:Loperamide is an opioid-receptor agonist and acts on the mu opioid receptors in the myenteric plexus of large intestine. It works by decreasing the motility of the circular and longitudinal smooth muscles of the intestinal wall. It is often used for this purpose in gastroenteritis, inflammatory bowel disease, and short bowel syndrome.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 27
Correct
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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: 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:
- Basic Sciences
- Physiology
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Question 28
Incorrect
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A terrorist running away from the police was shot in the back. The bullet hit his left lung halfway between its apex and the diaphragmatic surface. Which part of the lung was most likely to be injured?
Your Answer: Hilum
Correct Answer: Inferior lobe
Explanation:The oblique fissure of the left lung is so sharp that the posterior surface of the left lung is mostly composed of the inferior lobe so that the point halfway between the apex and the diaphragmatic surface of the lung would result in injury to the inferior lobe.
The hilum is the point on the medial surface of the lung where the structures that form the root of the lung enter and leave the lung.
The lingual on the other hand is part of the superior lobe of the left lung and it is part of the anterior and superior sides of the lung.
The middle lobe is only found on the right lung. -
This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 29
Incorrect
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Which of the following is most likely to cause hypovolaemic hypernatremia:
Your Answer: Burns
Correct Answer: Hyperalimentation
Explanation:Hypernatremia, characterised by a high serum sodium concentration, is rarely associated with volume overload (hypervolemia). A hypovolaemic hypernatremia may be seen during excessive administration of hypertonic sodium bicarbonate, hypertonic saline or hyperalimentation.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 30
Correct
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A 27-year-old female was admitted due to severe dehydration. The patient also complained of chest tightness, thus an ECG was requested. The ECG strip showed an isoelectric ST segment, upright T wave, with prominent U waves. What is the most likely electrolyte abnormality responsible for these ECG tracing?
Your Answer: Hypokalaemia
Explanation:U waves are prominent if it is >1-2mm or 25% of the height of the T wave. Abnormally prominent U waves are characteristically seen in severe hypokalaemia.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 31
Incorrect
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Which of the following coagulation factors cross-links fibrin?
Your Answer: Factor II
Correct Answer: Factor XIII
Explanation:Factor XIII, also known as fibrin stabilizing factor, is an enzyme of the coagulation cascade that crosslinks fibrin. Deficiency of FXIII may cause bleeding tendency but paradoxically, it may also predispose to thrombosis.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 32
Incorrect
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A 76 year old man who presented with lower back pain is diagnosed with prostatic carcinoma that has metastasized to his lumber spine. Which of the following markers is characteristically elevated?
Your Answer: Alpha-fetoprotein
Correct Answer: PSA
Explanation:Spread of prostatic carcinoma is common to the lumbar spine and pelvis. This results in osteoblastic metastases that will present as lower back pain with increased alkaline phosphatase, prostatic acid phosphates and PSA. PSA is more specific and a PSA > 10 ng/ml for any age is worrisome.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 33
Incorrect
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A 56 year old mechanic undergoes a live related renal transplant. He had a good urine output and the graft appeared well perfused at the end of the operation. However, on the ward he suddenly becomes anuric. Which of the following is the most likely cause?
Your Answer: Hyperacute rejection
Correct Answer: Renal artery thrombosis
Explanation:Acute renal artery thrombosis is a devastating complication of renal transplantation that can result in graft loss if not detected early. Surgical and technical errors are the major cause of renal artery thrombosis. Renal artery thrombosis usually presents with sudden onset oliguria or anuria accompanied by pain and tenderness over the graft site. Patients may develop thrombocytopenia due to platelet aggregation at the thrombosis site. The imaging modality of choice for diagnosis of renal artery thrombosis is colour Doppler sonography. Conventional, computed tomography (CT) and magnetic resonance (MR) angiography may also be used to confirm the presence of renal artery thrombosis. Although there are reports of successful resolution of post-transplant acute renal artery thrombosis with endovascular and surgical modalities such as percutaneous thrombus aspiration, intra-arterial injection of fibrinolytic agents and surgical thrombectomy, renal artery thrombosis usually results in ischemic necrosis and graft loss.
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This question is part of the following fields:
- Generic Surgical Topics
- Organ Transplantation
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Question 34
Incorrect
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A growing tumour is impinging on the lingual artery in the floor of the mouth. Which structure will experience decreased blood flow?
Your Answer: The parotid gland
Correct Answer: The sublingual gland
Explanation:The paired sublingual glands are major salivary glands in the mouth. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume. The gland receives its blood supply from the sublingual and submental arteries. The sublingual artery is a branch of the lingual artery, thus damage to the lingual artery will decrease the blood flow to the sublingual gland.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 35
Correct
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This structure divides the space between the lens and the cornea into the anterior and posterior chambers of the eye:
Your Answer: The iris
Explanation:The iris divides the space between the lens and the cornea into an anterior and a posterior chamber. The anterior cavity is filled with watery aqueous fluid, and the posterior cavity with a gel-like vitreous fluid. The anterior chamber of the eye is bounded in front by the posterior surface of the cornea; behind by the front of the iris and the central part of the lens. The posterior chamber is a narrow gap behind the peripheral part of the iris and in front of the suspensory ligament of the lens and the ciliary processes.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 36
Incorrect
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A 5 year old boy presents with an abnormal gait. On examination, his WCC was found to be 12 and ESR was 31. Past medical history shows a recent viral illness. Which of the following is the cause of these symptoms?
Your Answer: Septic arthritis
Correct Answer: Transient synovitis
Explanation:Transient synovitis (TS) is the most common cause of acute hip pain in children aged 3-10 years. The disease causes arthralgia and arthritis secondary to a transient inflammation of the synovium of the hip. Biopsy reveals only nonspecific inflammation and hypertrophy of the synovial membrane. Ultrasonography demonstrates an effusion that causes bulging of the anterior joint capsule. Synovial fluid has increased proteoglycans.
Unilateral hip or groin pain is the most common symptom reported; however, some patients with transient synovitis (TS) may report medial thigh or knee pain. Transient synovitis has the highest incidence rate among causes of nontraumatic hip pain in children. Guidelines for chronic hip pain have been established.Causes
No definitive cause of transient synovitis is known, although the following have been suggested:
– Patients with transient synovitis often have histories of trauma, which may be a cause or predisposing factor.
– One study found an increase in viral antibody titres in 67 of 80 patients with transient synovitis.
– Postvaccine or drug-mediated reactions and an allergic disposition have been cited as possible causes.The following studies may be indicated in transient synovitis (TS):
– CBC count: The white blood cell (WBC) count may be slightly elevated.
– Erythrocyte sedimentation rate (ESR) may be slightly elevated. One study found that the combination of an ESR greater than 20 mm/h and/or a temperature greater than 37.5°C identified 97% of individuals with septic hip. -
This question is part of the following fields:
- Generic Surgical Topics
- Orthopaedics
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Question 37
Correct
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Which of the following substances is most likely to cause pulmonary vasodilatation?
Your Answer: Nitric oxide
Explanation:In the body, nitric oxide is synthesised from arginine and oxygen by various nitric oxide synthase (NOS) enzymes and by sequential reduction of inorganic nitrate. The endothelium of blood vessels uses nitric oxide to signal the surrounding smooth muscle to relax, so dilating the artery and increasing blood flow. Nitric oxide/oxygen blends are used in critical care to promote capillary and pulmonary dilation to treat primary pulmonary hypertension in neonatal patients post-meconium aspiration and related to birth defects.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 38
Correct
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A 19 year old female presents with a firm mobile mass in the upper outer quadrant of her left breast. Which of the following could be the underlying disease process?
Your Answer: Fibroadenoma
Explanation:A fibroadenoma is a painless, unilateral, benign (non-cancerous) breast tumour that is a solid, not fluid-filled, lump. It occurs most commonly in women between the age of 14 to 35 years but can be found at any age. Fibroadenomas shrink after menopause, and therefore, are less common in post-menopausal women. Fibroadenomas are often referred to as a breast mouse due to their high mobility. Fibroadenomas are a marble-like mass comprising both epithelial and stromal tissues located under the skin of the breast. These firm, rubbery masses with regular borders are often variable in size.
Duct ectasia, also known as mammary duct ectasia, is a benign (non-cancerous) breast condition that occurs when a milk duct in the breast widens and its walls thicken. This can cause the duct to become blocked and lead to fluid build-up. It’s more common in women who are getting close to menopause. But it can happen after menopause, too.
Fat necrosis is a benign condition and does not increase the risk of developing breast cancer. It can occur anywhere in the breast and can affect women of any age. Men can also get fat necrosis, but this is very rare.
Breast cysts are a benign condition. They’re one of the most common causes of a breast lump, and can develop in either one or both breasts. It’s thought they develop naturally as the breast changes with age due to normal changes in hormone levels. It’s common to have more than one cyst. Breast cysts can feel soft or hard and can be any size, ranging from a few millimetres to several centimetres. They’re usually oval or round in shape and can develop quickly.
Atypical hyperplasia is a precancerous condition that affects cells in the breast. Atypical hyperplasia describes an accumulation of abnormal cells in the breast.
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This question is part of the following fields:
- Breast And Endocrine Surgery
- Generic Surgical Topics
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Question 39
Incorrect
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A neurotransmitter of the nigrostriatal pathway is:
Your Answer: Gamma-aminobutyric acid (GABA)
Correct Answer: Dopamine
Explanation:Dopamine acts as a neurotransmitter in the brain, activating dopamine receptors. It is also a neurohormone released from the hypothalamus. It plays an important role in the reward system. It is believed that dopamine provides a teaching signal to parts of the brain responsible for acquiring new motor sequences (behaviours), by activation of dopamine neurons when an unexpected reward is presented. Loss of dopamine neurones in the nigrostriatal pathway causes Parkinson’s disease. In the frontal lobes, dopamine controls the flow of information from other areas of the brain, and thus, dopamine disorders in this region can cause a decline in neurocognitive functions, especially memory, attention and problem solving. Reduced dopamine concentrations in the prefrontal cortex are thought to contribute to attention-deficit disorder and some symptoms of schizophrenia. Dopamine is also the primary neuroendocrine regulator of the secretion of prolactin from the anterior pituitary gland. Dopamine is also commonly associated with the pleasure system of the brain. This plays a key role in understanding the mechanism of action of drugs (such as cocaine and the amphetamines), which seem to be directly or indirectly related to the increase of dopamine.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 40
Incorrect
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A 52-year-old female presents with pain in her proximal femur. Imaging demonstrates a bone metastasis from an unknown primary site. CT scanning with arterial phase contrast shows that the lesion is hypervascular. From which of the following primary sites is the lesion most likely to have originated?
Your Answer: Thyroid
Correct Answer: Renal
Explanation:In females, the breasts and lungs are the most common primary disease sites; approximately 80% of cancers that spread to bone arise in these locations. In males, cancers of the prostate and lungs make up 80% of the carcinomas that metastasize to bone. The remaining 20% of primary disease sites in patients of both sexes are the kidney, gut, and thyroid, as well as sites of unknown origin.
On contrast-enhanced CT scans, RCC is usually solid, and decreased attenuation suggestive of necrosis is often present. Sometimes, RCC is a predominantly cystic mass, with thick septa and wall nodularity.
RCC may also appear as a completely solid and highly enhancing mass -
This question is part of the following fields:
- Oncology
- Principles Of Surgery-in-General
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Question 41
Incorrect
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A 14 year old boy is taken to the emergency room after complaining of sudden onset of pain in the left hemiscrotum despite not having any other urinary symptoms. The superior pole of the testis is tender on examination and the cremasteric reflex is particularly marked. What would be the underlying diagnosis?
Your Answer: Torsion of the testis
Correct Answer: Torsion of a testicular hydatid
Explanation:Answer: Torsion of a testicular hydatid
The appendix testis (or hydatid of Morgagni) is a vestigial remnant of the Müllerian duct, present on the upper pole of the testis and attached to the tunica vaginalis. It is present about 90% of the time. The appendix of testis can, occasionally, undergo torsion (i.e. become twisted), causing acute one-sided testicular pain and may require surgical excision to achieve relief. One third of patients present with a palpable blue dot discoloration on the scrotum. This is nearly diagnostic of this condition. If clinical suspicion is high for the serious differential diagnosis of testicular torsion, a surgical exploration of the scrotum is warranted. Torsion of the appendix of testis occurs at ages 0-15 years, with a mean at 10 years, which is similar to that of testicular torsion.
Occasionally a torsion of the hydatid of Morgagni can produce symptoms mimicking those created by a testicular torsion; a torsion of the hydatid, however, does not lead to any impairment of testicular function.
Absence of the cremasteric reflex is a sign of testicular torsion. This therefore confirms that the diagnosis is Torsion of a testicular hydatid. -
This question is part of the following fields:
- Generic Surgical Topics
- Urology
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Question 42
Correct
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A 66-year-old man complains of constant headaches. On physical examination, the only relevant sign is a dark brown mole located on left his arm which has grown in size over the years and is itchy and painful. A MRI of the brain revealed a solitary lesion at the grey-white junction in the right frontal lobe, without ring enhancement. This lesion is most likely to be:
Your Answer: Metastatic carcinoma
Explanation:The location of the mass at the grey–white junction is typical of a metastasis. The most frequent types of metastatic brain tumours originate in the lung, skin, kidney, breast and colon. These tumour cells reach the brain via the bloodstream. This patient is likely to have skin cancer, which caused the metastatic brain tumour.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 43
Correct
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A 35-year-old ultra marathon runner becomes severely dehydrated and collapses. This patient most likely has:
Your Answer: Decreased baroreceptor firing rate
Explanation:Baroreceptors are sensors located in the blood vessels of all vertebrate animals. They sense the blood pressure and relay the information to the brain, so that a proper blood pressure can be maintained. Acute dehydration results in decreased plasma volume and increased plasma osmolarity, since more water than salt is lost in sweat. The decrease in plasma volume leads to an inhibition of the baroreceptors and a lower firing rate. The increase in plasma osmolarity leads to increased ADH secretion and high plasma ADH levels, which increases water permeability of collecting duct cells. Therefore more water is reabsorbed by the kidneys and renal water excretion is low.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 44
Incorrect
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A 44-year old gentleman presented to the hospital in congestive cardiac failure. On further investigation, he was found to have a right-sided retroperitoneal mass. On enquiry, he gave a history of intermittent hypertensive attacks. 24-hour urine specimen revealed raised metanephrine and vanillylmandelic acid levels. What is the likely diagnosis?
Your Answer: Addison's disease
Correct Answer: Pheochromocytoma
Explanation:A neuroendocrine tumour of the chromaffin cells in adrenal medulla, pheochromocytoma secretes excessive catecholamines – adrenaline (epinephrine) and noradrenaline (norepinephrine). Pheochromocytomas are also known as the ‘10% tumour’. This is because 10% of them are bilateral, 10% are malignant, and 10% are extra-adrenal. Extra-adrenal paragangliomas (also known as extra-adrenal pheochromocytomas) are less common than pheochromocytomas and arise in the ganglia of sympathetic nervous system. Around 25% of pheochromocytomas are familial. Symptoms are described as feeling of ‘impending doom’, and include tachycardia, hypertension, palpitations, anxiety, headaches and pallor. Orthostatic hypertension is typically seen where there is a more than 100 mmHg fall in systolic pressure when the patient stands up. Pheochromocytomas can also lead to malignant hypertension. Diagnosis is by measurement of catecholamines and metanephrines in blood or in 24-hour urine, after exclusion of other possible causes such as stress, hypoglycaemia and drugs (methyldopa, dopamine agonists, ganglion-blocking antihypertensive). Imaging is also needed to localize the tumour. Localization of the tumour can also be done by Iodine-131 meta-iodobenzylguanidine (I131-MIBG) imaging.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 45
Correct
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If a 55-year old gentleman who has suffered a stroke, develops a tremor in his fingers that worsens on reaching for an object, what part of his brain is likely to be involved?
Your Answer: Cerebellum
Explanation:The cerebellum plays an important role in the integration of sensory perception and motor output. Multiple neural pathways link the cerebellum with the motor cortex and the spinocerebellar tract. The cerebellum uses the constant feedback on body position to fine-tune the movements and integrates these pathways. The patient described here has a characteristic cerebellar tremor that is a slow, broad tremor of the extremities and occurs at the end of a purposeful movement.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 46
Correct
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A patients sciatic nerve has been severed following a stab injury. What would be affected?
Your Answer: There would still be cutaneous sensation over the anteromedial surface of the thigh
Explanation:The sciatic nerve supplies nearly all of the sensation of the skin of the leg and the muscles of the back of the thigh, leg and foot. A transection of the sciatic nerve at its exit from the pelvis will affect all the above-mentioned functions except cutaneous sensation over the anteromedial surface of the thigh, which comes from the femoral nerve.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 47
Incorrect
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In the case of an injury to the sub sartorial canal, which of the following structures is most likely to be injured?
Your Answer: Nerve to sartorius
Correct Answer: Nerve to vastus medialis
Explanation:The adductor canal (sub sartorial canal) is situated in the middle third of the thigh.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 48
Incorrect
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When one is silently counting, what part of his brain will show increased regional cerebral blood flow (rCBF)?
Your Answer: Occipital cortex
Correct Answer: Supplementary motor area
Explanation:Regional cerebral blood flow (rCBF) increases in the superior speech cortex (supplementary motor area) during periods of silent counting, whereas speaking aloud will do so in the motor cortex and medial temporal lobe, along with the superior speech cortex.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 49
Correct
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At which cervical level does the common carotid artery bifurcate into the internal and external carotid arteries?
Your Answer: C4
Explanation:The common carotid arteries are present on the left and right sides of the body. These arteries originate from different sources, but follow symmetrical courses. The right common carotid originates in the neck from the brachiocephalic trunk; the left from the aortic arch in the thorax. These split into the external and internal carotid arteries at the upper border of the thyroid cartilage, at around the level of the fourth cervical vertebra.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 50
Incorrect
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A 27-yeaar-old woman is diagnosed with candidiasis and prescribed fluconazole. What is the mechanism of action of fluconazole?
Your Answer: Inhibits viral DNA polymerase
Correct Answer: Inhibits cytochrome P450
Explanation:Fluconazole is a triazole antifungal drug used in the treatment and prevention of superficial and systemic fungal infections. Like other imidazole- and triazole-class antifungals, fluconazole inhibits the fungal cytochrome P450 enzyme, 14-demethylase. It is used to treat candidiasis, blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and pityriasis versicolor.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 51
Incorrect
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Which of the following is likely to result in hematocolpos in a 12-year old girl?
Your Answer: Endometriosis
Correct Answer: Imperforate hymen
Explanation:Hematocolpos means accumulation of blood in vagina and hematometra is accumulation of blood in the uterus. These are most likely seen with an imperforate hymen; which is seen I 1 in 2000 females. If spontaneous resolution does not occur, treatment involves making a hole in the hymen to allow discharge of menstrual blood.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 52
Incorrect
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A 45-year old farmer was referred to the surgical clinic with complaints of pain in his right hypochondrium. Investigations confirmed the diagnosis of hepatocellular carcinoma with malignant ascites. According to you, what is the most likely cause of HCC in this patient?
Your Answer: Oestrogens
Correct Answer: Aflatoxin
Explanation:Aflatoxins are naturally occurring toxins produced by the Aspergillus fungus (most often, A. flavus and A. parasiticus). These organisms are common and their native habitat is soil, decaying vegetation and grains. They can contaminate the grain before harvest or after storage, more likely in high-humidity (at least 7%) or high temperature environment of after stressful conditions like drought. Aflatoxins are mycotoxins and also carcinogenic. They get metabolized in the liver to an epoxide, aflatoxin M1. High exposure can lead to acute necrosis, cirrhosis or liver carcinoma. These substances can cause haemorrhage, acute liver damage, oedema, and alteration in digestion, absorption and/or metabolism of nutrients. Although humans are susceptible to these toxins like all other animals, they have a high tolerance level and hence, rarely develop acute aflatoxicosis. However, children are particularly susceptible to exposure leading to growth impairment and delayed development. Chronic exposure carries a high risk of hepatic cancer, due to intercalation of its metabolite aflatoxin M1 into the DNA and alkylation of the bases because of its epoxide moiety.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 53
Incorrect
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After a car accident, a 30-year-old woman is alert and only has minor, superficial injuries. 2 hours later, she becomes unconscious and a CT scan reveals a convex, lens-shaped haemorrhage over the right parietal region. The most likely diagnosis is:
Your Answer: Subarachnoid haemorrhage
Correct Answer: Epidural haematoma
Explanation:Epidural haematomas are usually caused by arterial bleeding, classically due to damage to the middle meningeal artery by a temporal bone fracture. Symptoms develop within minutes to several hours after the injury and consist of increasing headache, decreased level of consciousness, hemiparesis and pupillary dilation with loss of light reactivity. Around 15–20% of epidural hematomas are fatal.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 54
Incorrect
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A 42 - year old male patient with an acute onset headache was brought in to the emergency department with suspicion of a subarachnoid haemorrhage (SAH). The SHO on call decided to have a diagnostic lumbar puncture after computed topography scan failed to support the suspicion. To perform a successful lumbar puncture without causing injury to the spine, which anatomical landmark should guide the SHO to locate the fourth vertebra for insertion of the spinal needle?
Your Answer: Umbilicus
Correct Answer: Iliac crest
Explanation:The safest spinal level for conducting a lumbar puncture, is at the level of the fourth lumbar vertebra. The anatomical landmark used to locate the fourth lumbar vertebra (L4), is the iliac crest. The needle can safely be inserted either above or below L4. The conus medullaris is at the level of the border of L1 and L2 so L4 is safely distant from it.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 55
Incorrect
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A recognised side-effect of prefrontal leukotomy is:
Your Answer: Receptive aphasia
Correct Answer: Confusion
Explanation:Used previously as a treatment for psychiatric disorders, prefrontal leucotomy severs the connection between the prefrontal cortical association area and the thalamus. This leads to functional isolation of the prefrontal and orbitofrontal association cortex. Thus, along with the desired reduction in anger and frustration, undesirable side effects included changes in mood and affect, as well as confusion.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 56
Incorrect
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A 40 year old teacher presents with a mass lesion in the upper outer quadrant of the right breast. Tests reveal that she has a 2cm mass lesion which on core biopsy is demonstrated to be invasive ductal carcinoma. A FNA of a bulky axillary lymph node contains malignant cells. What is the best course of action?
Your Answer: Simple mastectomy and sentinel node biopsy
Correct Answer: Wide local excision and axillary node clearance
Explanation:Axillary dissection is a surgical procedure that incises the axilla to identify, examine, or remove lymph nodes. Axillary dissection has been the standard technique used in the staging and treatment of the axilla in breast cancer.
Axillary dissection should be reserved for patients with proven axillary disease preoperatively or with a positive sentinel node biopsy.Axillary dissection is only therapeutic in patients who are node positive.
Wide local excision (Lumpectomy) is defined as complete surgical resection of a primary tumour with a goal of achieving widely negative margins (ideally a 1-cm margin around the lesion). It is applicable in most patients with stage I and stage II invasive carcinomas. This patient has a tumour size of 2cm which is small hence wide local excision should be done.
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This question is part of the following fields:
- Breast And Endocrine Surgery
- Generic Surgical Topics
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Question 57
Correct
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Which of the following brings about a reduction in gastric blood flow?
Your Answer: Vasopressin
Explanation:Gastric blood flow is increased by vagal stimulation, gastrin, histamine and acetylcholine as they stimulate gastric section and the production of vasodilator metabolites. Acetylcholine and histamine also have a direct action on the gastric arterioles. Similarly, gastric blood flow is reduced by inhibitors of secretion – catecholamines, secretin and vasopressin.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 58
Incorrect
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A 46 year old woman is taken to the A&E department with a full thickness burn on her chest which is well circumscribed. Her saturation was reduced to 92% on 15L of Oxygen, blood pressure of 104/63 mmHg and HR 106 bpm. What is the best management step?
Your Answer: Haemodialysis
Correct Answer: Escharotomy
Explanation:Answer: Escharotomy
Escharotomy is the surgical division of the nonviable eschar, which allows the cutaneous envelope to become more compliant. Hence, the underlying tissues have an increased available volume to expand into, preventing further tissue injury or functional compromise.
Full-thickness circumferential and near-circumferential skin burns result in the formation of a tough, inelastic mass of burnt tissue (eschar). The eschar, by virtue of this inelasticity, results in the burn-induced compartment syndrome. This is caused by the accumulation of extracellular and extravascular fluid within confined anatomic spaces of the extremities or digits. The excessive fluid causes the intracompartmental pressures to increase, resulting in collapse of the contained vascular and lymphatic structures and, hence, loss of tissue viability. The capillary closure pressure of 30 mm Hg, also measured as the compartment pressure, is accepted as that which requires intervention to prevent tissue death.
The circumferential eschar over the torso can lead to significant compromise of chest wall excursions and can hinder ventilation. Abdominal compartment syndrome with visceral hypoperfusion is associated with severe burns of the abdomen and torso. (A literature review by Strang et al found the prevalence of abdominal compartment syndrome in severely burned patients to be 4.1-16.6%, with the mean mortality rate for this condition in these patients to be 74.8%). Similarly, airway patency and venous return may be compromised by circumferential burns involving the neck.
Performing an escharotomy will therefore improve ventilation.
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This question is part of the following fields:
- Emergency Medicine And Management Of Trauma
- Principles Of Surgery-in-General
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Question 59
Incorrect
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All the following statements are FALSE regarding the ophthalmic division of the trigeminal nerve, except:
Your Answer: One of its branches gives motor innervation to the lacrimal gland
Correct Answer: The ophthalmic nerve is the smallest branch of the trigeminal nerve
Explanation:The ophthalmic nerve is the smallest of the three trigeminal divisions. The cutaneous branches of the ophthalmic nerve supply the conjunctiva, the skin over the forehead, the upper eyelid, and much of the external surface of the nose.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 60
Incorrect
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Electrophoresis is used to detect antibodies (immunoglobulins) in a blood sample from the umbilical artery of a new born. Which antibodies have the highest percentage in a new-born?
Your Answer: IgA
Correct Answer: IgG
Explanation:IgG is a monomeric immunoglobulin. It is formed by two heavy chains and two light chains and has two binding sites. Its is the most abundant antibody that is equally distributed in the blood and the tissues. It is the only antibody that can pass through the placenta and thus the only antibody present in the baby after it is born. There are four subclasses: IgG1 (66%), IgG2 (23%), IgG3 (7%) and IgG4 (4%). IgG1, IgG3 and IgG4 cross the placenta easily
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 61
Incorrect
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What is the basic chemical reaction that takes place in the breakdown of complex foodstuffs?
Your Answer: Oxidation
Correct Answer: Hydrolysis
Explanation:Breakdown of complex food into simpler compounds is achieved by hydrolysis, with the help of different enzymes specific for different compounds.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 62
Incorrect
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A new-born was found to have an undeveloped spiral septum in the heart. This is characteristic of which of the following?
Your Answer: Aortic valve stenosis
Correct Answer: Persistent truncus arteriosus
Explanation:Persistent truncus arteriosus is a congenital heart disease that occurs when the primitive truncus does not divide into the pulmonary artery and aorta, resulting in a single arterial trunk. The spiral septum is created by fusion of a truncal septum and the aorticopulmonary spiral septum. Incomplete development of these septa results in incomplete separation of the common tube of the truncus arteriosus and the aorticopulmonary trunk.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 63
Incorrect
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A 29-year-old man with gunshot to the abdomen is transferred to the operating theatre, following his arrival in the A&E department. He is unstable and his FAST scan is positive. During the operation, extensive laceration to the right lobe of the liver and involvement of the IVC are found, along with massive haemorrhage. What should be the most appropriate approach to blood component therapy?
Your Answer: Avoid use of O negative blood
Correct Answer:
Explanation:There is strong evidence to support haemostatic resuscitation in the setting of massive haemorrhage due to trauma. This advocates the use of 1:1:1 ratio.
Uncontrolled haemorrhage accounts for up to 39% of all trauma-related deaths. In the UK, approximately 2% of all trauma patients need massive transfusion. Massive transfusion is defined as the replacement of a patient’s total blood volume in less than 24 hours or the acute administration of more than half the patient’s estimated blood volume per hour. During acute bleeding, the practice of haemostatic resuscitation has been shown to reduce mortality rates. It is based on the principle of transfusion of blood components in fixed ratios. For example, packed red cells, FFP, and platelets are administered in a ratio of 1:1:1.
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This question is part of the following fields:
- Emergency Medicine And Management Of Trauma
- Principles Of Surgery-in-General
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Question 64
Incorrect
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The specimen sent to the pathologist for examination was found to be benign. Which one of the following is most likely a benign tumour?
Your Answer: Adenocarcinoma
Correct Answer: Warthin’s tumour
Explanation:Warthin’s tumour is also known as papillary cystadenoma lymphomatosum. It is a benign cystic tumour of the salivary glands containing abundant lymphocytes and germinal centres. It has a slightly higher incidence in males and most likely occur in older adults aged between 60 to 70 years. This tumour is also associated with smoking. Smokers have an eight-fold greater risk in developing the tumour compared to non-smokers.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 65
Incorrect
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The gastrosplenic ligament also known as the gastrolienal ligament is the structure that connects the greater curvature of the stomach to the hilum of the spleen. Which of the following arteries would most likely be injured if a surgeon accidentally tore this ligament?
Your Answer: Hepatic artery proper
Correct Answer: Short gastric
Explanation:The short gastric arteries arise from the end of the splenic arteries and form five to seven branches. The short gastric arteries inside the gastrosplenic ligament from the left to the right, supply the greater curvature of the stomach. The hepatic artery proper runs inside the hepatoduodenal ligament. The right gastric artery and the left gastric artery are contained in the hepatogastric ligament. The caudal pancreatic artery branches off from the splenic artery and supplies the tail of the pancreas. The middle colic artery supplies the transverse colon. The splenic artery does not travel in the gastrosplenic ligament and so it would not be damaged by a tear to this ligament.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 66
Incorrect
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The chest X-ray of a 72 year old patient reveals the presence of a round lesion containing an air-fluid level in the left lung. These findings are most probably suggestive of:
Your Answer: Septicaemia
Correct Answer: Lung abscess
Explanation:Lung abscesses are collections of pus within the lung that arise most commonly as a complication of aspiration pneumonia caused by oral anaerobes. Older patients are more at risk due to poor oral hygiene, gingivitis an inability to handle their oral secretions due to other diseases. Chest X-ray most commonly reveals the appearance of an irregularly shaped cavity with an air-fluid level.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 67
Correct
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Destruction of the ventromedial nucleus of the hypothalamus will result in:
Your Answer: Loss of satiety
Explanation:The ventromedial nucleus of the hypothalamus is divided into an anterior and a superior part. The anterior part controls the female sexual drive, whereas the superior part is responsible for satiety. Destruction of the superior part of the nucleus will result in overeating, as no signal tells the body that it is satisfied.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 68
Incorrect
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An 80 year old woman is undergoing excision of a basal cell carcinoma from her periorbital region under local anaesthesia. Medical history reveals multiple medical comorbities. Which medication should be stopped prior to surgery?
Your Answer: Gliclazide
Correct Answer: Aspirin
Explanation:Answer: Aspirin
Aspirin increases bleeding time when taken orally. Aspirin causes several different effects in the body, mainly the reduction of inflammation, analgesia (relief of pain), the prevention of clotting, and the reduction of fever. Much of this is believed to be due to decreased production of prostaglandins and TXA2. Aspirin’s ability to suppress the production of prostaglandins and thromboxanes is due to its irreversible inactivation of the cyclooxygenase (COX) enzyme. Cyclooxygenase is required for prostaglandin and thromboxane synthesis. Prostaglandins are local chemical messengers that exert multiple effects including but not limited to the transmission of pain information to the brain, modulation of the hypothalamic thermostat, and inflammation. They are produced in response to the stimulation of phospholipids within the plasma membrane of cells resulting in the release of arachidonic acid (prostaglandin precursor). Thromboxanes are responsible for the aggregation of platelets that form blood clots.
Low-dose, long-term aspirin use irreversibly blocks the formation of thromboxane A2 in platelets, producing an inhibitory effect on platelet aggregation.Antihypertensive and antidiabetic medications do not need to be stopped when a patient is undergoing local anaesthesia. Steroid (Prednisolone) use cannot be stopped abruptly; tapering the drug gives the adrenal glands time to return to their normal patterns of secretion. Withdrawal symptoms and signs (weakness, fatigue, decreased appetite, weight loss, nausea, vomiting, diarrhoea, abdominal pain) can mimic many other medical problems. Some may be life-threatening.
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This question is part of the following fields:
- Peri-operative Care
- Principles Of Surgery-in-General
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Question 69
Incorrect
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Macrolides are a group of antibiotics commonly used to treat respiratory tract and soft-tissue infections. Which of the following antibiotics is a macrolide?
Your Answer: Vancomycin
Correct Answer: Erythromycin
Explanation:Erythromycin is a macrolide antibiotic used in the treatment of several bacterial infections, including respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the new-born.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 70
Incorrect
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A 14 year old boy is suspected of having CSF rhinorrhoea after sustaining a basal skull fracture. Which laboratory test would be able to accurately detect the presence of CSF?
Your Answer: Lab stix testing for protein
Correct Answer: Beta 2 transferrin assay
Explanation:Answer: Beta 2 transferrin assay
Beta-2-transferrin is a protein found only in CSF and perilymph. Since 1979, beta-2-transferrin has been used extensively by otolaryngologists in the diagnosis of CSF rhinorrhoea and skull-base cerebrospinal fluid fistulas. With sensitivity of 94% – 100%, and specificity of 98% – 100%, this assay has become the gold standard in detection of CSF leakage. CSF rhinorrhoea is characterized by clear or xanthochromic watery rhinorrhoea that may not become apparent until nasal packing is removed.
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This question is part of the following fields:
- Emergency Medicine And Management Of Trauma
- Principles Of Surgery-in-General
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Question 71
Incorrect
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A 5-year-old child presents with fever and otalgia. Greenish pustular discharge was seen in his left ear during physical examination. The patient is diagnosed with otitis externa. Which of the following organisms most likely caused the infection?
Your Answer: Moraxella catarrhalis
Correct Answer: Pseudomonas aeruginosa
Explanation:P. aeruginosa is a multidrug resistant pathogen recognised for its ubiquity, its advanced antibiotic resistance mechanisms and its association with serious illnesses – especially hospital-acquired infections such as ventilator-associated pneumonia and various septic syndromes. The species name aeruginosa is a Latin word meaning verdigris (copper rust), referring to the blue-green colour of laboratory cultures of the species. This blue-green pigment is a combination of two metabolites of P. aeruginosa, pyocyanin (blue) and pyoverdine (green), which impart the blue-green characteristic colour of cultures.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 72
Incorrect
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The blood investigations of a 30-year old man with jaundice revealed the following : total bilirubin 6.5 mg/dl, direct bilirubin 1.1 mg/dl, indirect bilirubin 5.4 mg/dl and haemoglobin 7.3 mg/dl. What is the most likely diagnosis out of the following?
Your Answer: Cholangiocarcinoma
Correct Answer: Haemolysis
Explanation:Hyperbilirubinemia can be caused due to increased bilirubin production, decreased liver uptake or conjugation, or decreased biliary excretion. Normal bilirubin level is less than 1.2 mg/dl (<20 μmol/l), with most of it unconjugated. Elevated unconjugated bilirubin (indirect bilirubin fraction >85%) can occur due to haemolysis (increased bilirubin production) or defective liver uptake/conjugation (Gilbert syndrome). Such increases are less than five-fold usually (<6 mg/dl or <100 μmol/l) unless there is coexistent liver disease.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 73
Incorrect
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A 56 year old man, on his 8th day following a left hemicolectomy, complains of swinging pyrexia over the past 48 hours. Clinical examination is significant for an ileus. Which of the following investigations would be the most appropriate?
Your Answer: Erect chest x-ray
Correct Answer: Abdominal CT scan with IV contrast
Explanation:Abdominal CT with IV contrast would be carried out in this case and this presentation has most likely resulted due to an anastomotic leak with abscess formation which is a common complication following surgery. This can occur in any of the branches and anticipating the likely complication and appropriate avoidance will minimize their occurrence. Detailed imaging is required to allow accurate diagnosis and further planning.
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This question is part of the following fields:
- Principles Of Surgery-in-General
- Surgical Technique And Technology
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Question 74
Incorrect
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What is the 5 year survival rate of a patient who is diagnosed with stage III colon cancer, who underwent successful resection and completed the prescribed session of adjuvant chemotherapy?
Your Answer: 20-30%
Correct Answer: 30%–60%
Explanation:In this patient who has stage III colon cancer, the survival rate is 30-60%. For stage I or Dukes’ stage A disease, the 5-year survival rate after surgical resection exceeds 90%. For stage II or Dukes’ stage B disease, the 5-year survival rate is 70%–85% after resection, with or without adjuvant therapy. For stage III or Dukes’ stage C disease, the 5-year survival rate is 30%– 60% after resection and adjuvant chemotherapy and for stage IV or Dukes’ stage D disease, the 5-year survival rate is poor (approximately 5%).
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 75
Incorrect
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A 1 day old baby girl is born with severe respiratory compromise. She is seen to have a scaphoid abdomen and an absent apex beat. Which anomaly does this baby have?
Your Answer:
Correct Answer: Bochdalek hernia
Explanation:Answer: Bochdalek hernia
A Bochdalek hernia is one of two forms of a congenital diaphragmatic hernia, the other form being Morgagni hernia. A Bochdalek hernia is a congenital abnormality in which an opening exists in the infant’s diaphragm, allowing normally intra-abdominal organs (particularly the stomach and intestines) to protrude into the thoracic cavity. In the majority of patients, the affected lung will be deformed, and the resulting lung compression can be life-threatening. Bochdalek hernias occur more commonly on the posterior left side (85%, versus right side 15%).
In normal Bochdalek hernia cases, the symptoms are often observable simultaneously with the baby’s birth. A few of the symptoms of a Bochdalek Hernia include difficulty breathing, fast respiration and increased heart rate. Also, if the baby appears to have cyanosis (blue-tinted skin) this can also be a sign. Another way to differentiate a healthy baby from a baby with Bochdalek Hernia, is to look at the chest immediately after birth. If the baby has a Bochdalek Hernia it may appear that one side of the chest cavity is larger than the other and or the abdomen seems to be scaphoid (caved in).
Situs inversus (also called situs transversus or oppositus) is a congenital condition in which the major visceral organs are reversed or mirrored from their normal positions. The normal arrangement of internal organs is known as situs solitus while situs inversus is generally the mirror image of situs solitus. Although cardiac problems are more common than in the general population, most people with situs inversus have no medical symptoms or complications resulting from the condition, and until the advent of modern medicine it was usually undiagnosed. In the absence of congenital heart defects, individuals with situs inversus are homeostatically normal, and can live standard healthy lives, without any complications related to their medical condition. There is a 5–10% prevalence of congenital heart disease in individuals with situs inversus totalis, most commonly transposition of the great vessels. The incidence of congenital heart disease is 95% in situs inversus with levocardia.
Cystic fibrosis is a progressive, genetic disease that causes persistent lung infections and limits the ability to breathe over time. In people with CF, mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause the CFTR protein to become dysfunctional. When the protein is not working correctly, it’s unable to help move chloride — a component of salt — to the cell surface. Without the chloride to attract water to the cell surface, the mucus in various organs becomes thick and sticky. In the lungs, the mucus clogs the airways and traps germs, like bacteria, leading to infections, inflammation, respiratory failure, and other complications.
Necrotizing enterocolitis (NEC) is a medical condition where a portion of the bowel dies. It typically occurs in new-borns that are either premature or otherwise unwell. Symptoms may include poor feeding, bloating, decreased activity, blood in the stool, or vomiting of bile.
The exact cause is unclear. Risk factors include congenital heart disease, birth asphyxia, exchange transfusion, and premature rupture of membranes. The underlying mechanism is believed to involve a combination of poor blood flow and infection of the intestines. Diagnosis is based on symptoms and confirmed with medical imaging.Morgagni hernias are one of the congenital diaphragmatic hernias (CDH), and is characterized by herniation through the foramen of Morgagni. When compared to Bochdalek hernias, Morgagni hernias are:
-anterior
-more often right-sided (,90%)
-small
-rare (,2% of CDH)
-at low risk of prolapseOnly ,30% of patients are symptomatic. New-borns may present with respiratory distress at birth similar to a Bochdalek hernia. Additionally, recurrent chest infections and gastrointestinal symptoms have been reported in those with previously undiagnosed Morgagni hernia.
The image of the transverse colon is herniated into the thoracic cavity, through a mid line defect and this indicates that it is a Morgagni hernia since the foramen of a Morgagni hernia occurs in the anterior midline through the sternocostal hiatus of the diaphragm, with 90% of cases occurring on the right side.Clinical manifestations of congenital diaphragmatic hernia (CDH) include the following:
Early diagnosis – Right-side heart; decreased breath sounds on the affected side; scaphoid abdomen; bowel sounds in the thorax, respiratory distress, and/or cyanosis on auscultation; CDH can often be diagnosed in utero with ultrasonography (US), magnetic resonance imaging (MRI), or both
Late diagnosis – Chest mass on chest radiography, gastric volvulus, splenic volvulus, or large-bowel obstruction
Congenital hernias (neonatal onset) – Respiratory distress and/or cyanosis occurs within the first 24 hours of life; CDH may not be diagnosed for several years if the defect is small enough that it does not cause significant pulmonary dysfunction
Congenital hernias (childhood or adult onset) – Obstructive symptoms from protrusion of the colon, chest pain, tightness or fullness the in chest, sepsis following strangulation or perforation, and many respiratory symptoms occur. -
This question is part of the following fields:
- Generic Surgical Topics
- The Abdomen
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Question 76
Incorrect
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What is the normal amount of oxygen that is carried in the blood?
Your Answer:
Correct Answer: 20 ml oxygen/100 ml blood
Explanation:Normally, 100 ml of blood contains 15g haemoglobin and a single gram of haemoglobin can bind to 1.34 ml oxygen when 100% saturated. Thus, 15 × 1.34 = 20 ml O2/100 ml blood. The haemoglobin in venous blood that is leaving the tissues is about 75% saturated with oxygen, and hence it carries about 15 ml O2/100 ml venous blood. This implies that for each 10 ml of blood, 5 ml oxygen is transported to the tissues. With a p(O2) > 100 mm Hg, only 3 ml of oxygen is dissolved in every one litre of plasma. By increasing the pA(O2) by breathing 100% oxygen, one can add an extra amount of oxygen in the plasma, but the amount of oxygen carried by haemoglobin will not increase significantly as it is already > 95% saturated.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 77
Incorrect
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Which of the following diseases affects young adults, causing pain in any bone -particularly long bones- which worsens at night, and is typically relieved by common analgesics, such as aspirin?
Your Answer:
Correct Answer: Osteoid osteoma
Explanation:Osteoid osteoma, which tends to affect young adults, can occur in any bone but is most common in long bones. It can cause pain (usually worse at night) that is typically relieved by mild analgesics, such as non-steroidal anti-inflammatory drugs. X-ray findings include a small radiolucent zone surrounded by a larger sclerotic zone.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 78
Incorrect
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What is the percentage of bone calcium that is freely exchangeable with the extracellular fluid that is available for buffering changes in the calcium ion balance?
Your Answer:
Correct Answer: 1%
Explanation:Around 1% of calcium in the body is available for buffering changes in calcium ion balance. These are mainly derived from the bone that are freely exchangeable with extracellular fluid.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 79
Incorrect
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The primary motor cortex is located in the:
Your Answer:
Correct Answer: Precentral gyrus
Explanation:The primary motor cortex is located in the dorsal part of the precentral gyrus and the anterior bank of the central sulcus. The precentral gyrus lies anterior to the postcentral gyrus and is separated from it by a central sulcus. Its anterior border is the precentral sulcus, while inferiorly it borders to the lateral fissure (Sylvian fissure).
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 80
Incorrect
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A 7-year-old boys undergoes a testicular biopsy after a tumour is found in his right testis. Elements similar to hair and teeth are found in it. What kind of tumour is this?
Your Answer:
Correct Answer: Teratoma
Explanation:A teratoma is a tumour containing tissue elements that are similar to normal derivatives of more than one germ layer. They usually contain skin, hair, teeth and bone tissue and are more common in children, behaving as a benign tumour. After puberty, they are regarded as malignant and can metastasise.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 81
Incorrect
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During an operation to repair a hiatal hernia, the coeliac branch of the posterior vagal trunk is injured. This damage would affect muscular movements as well as some secretory activities of the gastrointestinal tract. Which gastrointestinal segment is LEAST likely to be affected?
Your Answer:
Correct Answer: Sigmoid colon
Explanation:The vagus nerve supplies the parasympathetic fibres to the abdominal structures that are receive arterial supply from the coeliac trunk or superior mesenteric artery i.e. up to the transverse colon. The end of the transverse colon and the gastrointestinal structures distal to this point receive parasympathetic innervation from the pelvic splanchnic nerves and blood from the inferior mesenteric artery(IMA). The ascending colon, caecum, jejunum and ileum would all, thus, be affected by this damage. Sigmoid colon would not be affected.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 82
Incorrect
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A 40 year old woman, who is under anaesthesia for an elective procedure, received an antibiotic injection. She immediately developed a rash and her airway constricted raising the airway pressure. Which mechanism is responsible for this reaction?
Your Answer:
Correct Answer: Type I hypersensitivity
Explanation:Type I hypersensitivity reaction is an immediate reaction that occurs due to binding of the antigen with antibodies attached to mast cells in a previously sensitized person. It has an immediate phase, which is characterised by vasodilation, leakage of plasma, smooth muscle spasm, or glandular secretions. This manifests in about 5-30 min and usually resolves within 60 mins. The delayed phase follows after 24 hours and can persist up to several days. It is due to infiltration of eosinophils, neutrophils, basophils and CD4+ cells and leads to tissue destruction. The nature of the reaction varies according to the site. It can take the form of skin allergy, hives, allergic rhinitis, conjunctivitis, bronchial asthma or food allergy.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 83
Incorrect
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When at rest, which of the following will be higher in a marathon runner compared to an untrained individual?
Your Answer:
Correct Answer: Cardiac stroke volume
Explanation:Cardiac muscle hypertrophy is seen in trained athletes as compared to the normal population. This hypertrophy results in higher stroke volume at rest and increased cardiac reserve (maximum cardiac output during exercise). However, the cardiac output at rest is almost the same in both trained and untrained people. This is because in trained athletes, the heart rate is slower, even up to 40-50 beats/min. There is minimal affect of athletic training on oxygen consumption and respiratory rate.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 84
Incorrect
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A man came to the hospital complaining of a sensation of pins and needles in the dorsum of the thumb and digits 1 and 2. On further examination they found that he had weakness in wrist dorsiflexion and finger extension. Which nerve do you think is injured in this case?
Your Answer:
Correct Answer: Radial
Explanation:The radial nerve can be injured in multiple sites along its course in the upper limb, and each site has its own presentation. The major complaint is wrist drop which if high above the elbow, can cause numbness of the forearm and hand. It can last for several days or weeks. The most common site of compression for the radial nerve is at the proximal forearm in the area of the supinator muscles.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 85
Incorrect
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A 15 year old girl is diagnosed with familial adenomatous polyposis. Which of the following is the most appropriate recommended step in management?
Your Answer:
Correct Answer: Surveillance annual flexible sigmoidoscopy from age 13 years until age 30 years
Explanation:Answer: Surveillance annual flexible sigmoidoscopy from age 13 years until age 30 years.
Familial adenomatous polyposis (FAP) is the most common adenomatous polyposis syndrome. It is an autosomal dominant inherited disorder characterized by the early onset of hundreds to thousands of adenomatous polyps throughout the colon. If left untreated, all patients with this syndrome will develop colon cancer by age 35-40 years. In addition, an increased risk exists for the development of other malignancies.
Most patients with FAP are asymptomatic until they develop cancer. As a result, diagnosing presymptomatic patients is essential.Of patients with FAP, 75%-80% have a family history of polyps and/or colorectal cancer at age 40 years or younger.
Nonspecific symptoms, such as unexplained rectal bleeding (haematochezia), diarrhoea, or abdominal pain, in young patients may be suggestive of FAP.
In a minority of FAP families a mutation cannot be identified and so annual flexible sigmoidoscopy should be offered to at risk family members from age 13–15 years until age 30, and at three to five year intervals thereafter until age 60 years.
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This question is part of the following fields:
- Colorectal Surgery
- Generic Surgical Topics
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Question 86
Incorrect
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A 70-year old man who is suspected to have a perforated colonic diverticulum is explored in theatre through a midline incision. This incision will be through the:
Your Answer:
Correct Answer: Linea alba
Explanation:The linea alba is the point where this incision was made. It is a tendinous raphe in the midline of the abdomen extending between the xiphoid process and the symphysis pubis. It is placed between the medial borders of the recti and is formed by the blending of the aponeuroses of the external and internal obliques and transversi.
The linea aspera is a vertical ridge on the posterior surface of the femur.
The arcuate line is the inferior border of the posterior rectus sheath behind the rectus abdominis muscle.
The semilunar line is the lateral margin of the rectus abdominis.
The iliopectineal line is a line on the pelvic bones formed by the arcuate line of the ilium and the pectineal line of the pubis. -
This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 87
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:
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:
- Basic Sciences
- Physiology
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Question 88
Incorrect
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Which of the following muscles is solely contained in the anterior triangle of the neck and divides the anterior triangle into three smaller triangles?
Your Answer:
Correct Answer: Digastric
Explanation:The digastric muscle is a small muscle located under the jaw. It lies below the body of the mandible, and extends, in a curved form, from the mastoid process to the symphysis menti. The digastric divides the anterior triangle of the neck into three smaller triangles:
– The submaxillary triangle, bounded above by the lower border of the body of the mandible and a line drawn from its angle to the sternocleidomastoid, below by the posterior belly of the digastric and the stylohyoid and in front by the anterior belly of the digastric
– The carotid triangle, bounded above by the posterior belly of the digastric and stylohyoid, behind by the sternocleidomastoid and below by the omohyoid
– The suprahyoid or submental triangle, bounded laterally by the anterior belly of the digastric, medially by the midline of the neck from the hyoid bone to the symphysis menti and inferiorly by the body of the hyoid bone. -
This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 89
Incorrect
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A young girl who presented with a clinical picture of type I hypersensitivity reaction with eosinophilia is most likely to have?
Your Answer:
Correct Answer: Liver flukes
Explanation:Usually a parasitic infection will be associated with a type I hypersensitivity reaction.
Amyloid deposition will not cause an immune reaction.
Organic dust will lead to a type III hypersensitivity reaction.
Cell mediated as well as humoral immune mechanism play a part in syphilis, but they are do not specifically cause a type I reaction.
Malaria is cause by plasmodium and is not cause of a hypersensitivity reaction.
Atopic dermatitis will not be accompanied by eosinophilia. -
This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 90
Incorrect
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When the pitch of a sound increases, what is the physiological response seen in the listener?
Your Answer:
Correct Answer: The location of maximal basilar membrane displacement moves toward the base of the cochlea
Explanation:An increase in the frequency of sound waves results in a change in the position of maximal displacement of the basilar membrane in the cochlea. Low pitch sound produces maximal displacement towards the cochlear apex and greatest activation of hair cells there. With an increasing pitch, the site of greatest displacement moves towards the cochlear base. However, increased amplitude of displacement, increase in the number of activated hair cells, increased frequency of discharge of units in the auditory nerve and increase in the range of frequencies to which such units respond, are all seen in increases in the intensity or a sound stimulus.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
