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Question 1
Correct
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A 53-year-old female with a history of rheumatoid presents with a suspected septic knee joint. A diagnostic aspiration is performed and sent to microbiology. Which of the organisms below is most likely to be responsible?
Your Answer: Staphylococcus aureus
Explanation:Septic arthritis, also known as infectious arthritis, may represent a direct invasion of the joint space by various microorganisms, most commonly caused by bacteria.
Neisseria gonorrhoeae remains the most common pathogen (75% of cases) among younger sexually active individuals.
Staphylococcus aureus infection causes the vast majority of acute bacterial arthritis cases in adults and in children older than 2 years. -
This question is part of the following fields:
- Clinical Microbiology
- Principles Of Surgery-in-General
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Question 2
Incorrect
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A 26 year old policewoman is admitted with bloody diarrhoea. She has been passing 10 stools per day, Hb-8.1, albumin-21. Her stool culture is negative and there is evidence of colitis on endoscopy. She has been on intravenous steroids for 5 days and has now developed megacolon. Her haemoglobin is falling and inflammatory markers are static. Which of the following is the best course of action?
Your Answer:
Correct Answer: Undertake a sub total colectomy and end ileostomy
Explanation:The operation aims to remove most of your large bowel including the blood supply and associated lymph glands and leave the rectum behind. It is most commonly recommended for inflammatory bowel disease like ulcerative colitis and Crohn’s disease.
It is also recommended for other bowel conditions like familial adenomatous polyposis, and when there is more than one bowel cancer.
In inflammatory bowel disease such as ulcerative colitis the small bowel is brought out to the skin of the tummy as an ileostomy and the remaining bowel (rectum) is closed off and left inside. In other conditions where possible, the two ends of the remaining healthy bowel (small bowel to rectum) are re-joined (an anastomosis). Most
people therefore do not require a stoma. However some people benefit from having a stoma made depending on circumstances regarding:
1) Their general state of health (heart disease, lung disease, diabetes, vascular disease, smoking, steroid medications, being undernourished);
2) Factors which cannot be seen until the surgeon can see inside your tummy (more extensive disease than originally thought, extensive pelvic scarring from previous surgery or other treatment, excessive bleeding).
Temporary stomas are made to divert faeces away from the join (de-functioning) to give the best chance to heal if there is concern it may be slow to heal.Emergency indications for surgical intervention in severe UC include free perforation, haemorrhage or systemic instability. An urgent indication for colectomy is a severe attack that is unresponsive to medical therapy.
In the setting of severe UC, the procedure of choice is subtotal colectomy and ileostomy. The residual rectal disease is controllable in most patients. In general, there are advantages to the subtotal colectomy approach, including a lower morbidity if pelvic dissection is not performed, preservation of the rectum so that reconstructive procedures can be performed later, and allowing the definitive procedure to be deferred to an optimal situation when the patient is off immunosuppressive medications and has improved nutritional status. Usually, the staged reconstruction with IPAA or definitive total proctocolectomy is performed several months later.
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This question is part of the following fields:
- Colorectal Surgery
- Generic Surgical Topics
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Question 3
Incorrect
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A 65-year-old smoker presents with painless haematuria, urinary frequency and urgency. He is diagnosed with bladder cancer. Which is the most likely type?
Your Answer:
Correct Answer: Transitional cell carcinoma
Explanation:90% of bladder cancers are transitional cell carcinomas derived from the bladder urothelium. Risk factors include industrial chemicals, smoking and infection. Schistosomiasis and bladder stones predispose to the squamous cell variety.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 4
Incorrect
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An old man fell and fractured a carpal bone articulating with the pisiform bone. Which bone was most likely fractured?
Your Answer:
Correct Answer: Triquetral
Explanation:The pisiform bone has an oval facet for articulation with the triquetral bone. The pisiform bone is a sesamoid bone, and is anterior to the other carpal bones.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 5
Incorrect
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The glossopharyngeal nerve provides the parasympathetic innervation of the:
Your Answer:
Correct Answer: Parotid salivary gland
Explanation:The glossopharyngeal nerve provides parasympathetic innervation for the parotid salivary gland via the auriculotemporal nerve. The facial nerve supplies the parasympathetic innervation of the lacrimal, nasal, sublingual and submandibular glands.
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 6
Incorrect
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Which nuclei of the posterior grey column of the spinal cord are likely affected in a patient who has lost the sensation of pain and temperature?
Your Answer:
Correct Answer: Substantia gelatinosa
Explanation:Substantia gelatinosa is one of the nuclei in the posterior grey column along side other posterior grey column nuclei like the nucleus dorsalis, nucleus proprius, and posteromarginal nucleus. These nuclei are a collection of cells in the posterior grey area found in throughout the spinal cord. The substantia gelatinosa receives direct input from the dorsal nerve roots (sensory), especially from thermoreceptors and nociceptors (receptors for temperature and pain).
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 7
Incorrect
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A 28 year old man presents to his doctor with a painful mass underneath his left mandible. The mass has appeared over the previous week with the pain worsening as the lump has increased in size. On examination, a 3 cm mass underneath his mandible is seen but there is no associated lymphadenopathy. What is the most likely diagnosis?
Your Answer:
Correct Answer: Submandibular gland calculus
Explanation:Sialolithiasis (also termed salivary calculi, or salivary stones), is a condition where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland (also termed Wharton’s duct).
Signs and symptoms are variable and depend largely upon whether the obstruction of the duct is complete or partial, and how much resultant pressure is created within the gland.
The development of infection in the gland also influences the signs and symptoms:
– Pain, which is intermittent, and may suddenly get worse before mealtimes, and then slowly get better (partial obstruction).
– Swelling of the gland, also usually intermittent, often suddenly appearing or increasing before mealtimes, and then slowly going down (partial obstruction).
– Tenderness of the involved gland.
– Palpable hard lump, if the stone is located near the end of the duct. If the stone is near the submandibular duct orifice, the lump may be felt under the tongue.
– Lack of saliva coming from the duct (total obstruction).
– Erythema (redness) of the floor of the mouth (infection).
– Pus discharging from the duct (infection).
– Cervical lymphadenitis (infection).
– Bad Breath.
– Rarely, when stones form in the minor salivary glands, there is usually only slight local swelling in the form of a small nodule and tenderness. -
This question is part of the following fields:
- Generic Surgical Topics
- Head And Neck Surgery
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Question 8
Incorrect
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An 8 year old boy presents with bleeding from the nose. From which area did the bleeding most likely originate?
Your Answer:
Correct Answer: Kiesselbach's plexus
Explanation:Answer: Kiesselbach’s plexus
Epistaxis is defined as acute haemorrhage from the nostril, nasal cavity, or nasopharynx. The source of 90% of anterior nosebleeds within the Kiesselbach’s plexus (also known as Little’s area) on the anterior nasal septum.
Kiesselbach’s plexus (Kiesselbach’s area or Little’s area) is a vascular region of the anteroinferior nasal septum that comprises four arterial anastomoses:
1)anterior ethmoidal artery – a branch of the ophthalmic artery
2)sphenopalatine artery -
This question is part of the following fields:
- Generic Surgical Topics
- Head And Neck Surgery
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Question 9
Incorrect
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What is formed when the ductus deferens unites with the duct of the seminal vesicle?
Your Answer:
Correct Answer: Ejaculatory duct
Explanation:The deferens is a cylindrical structure with dense walls and an extremely small lumen It is joined at an acute angle by the duct of the seminal vesicles to form the ejaculatory duct, which traverses the prostate behind it’s middle lobe and opens into the prostatic portion of the urethra, close to the orifice of the prostatic utricle.
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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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A 42 year old man presents with end stage renal failure and is prepared to receive a kidney from his best friend. HLA testing showed that they are not a 100% match and he is given immunosuppressant therapy for this. Three months later when his renal function is assessed, he showed signs of deteriorating renal function, with decreased renal output, proteinuria of +++ and RBCs in the urine. He was given antilymphocyte globulins and his condition reversed. During the crisis period the patient is likely to be suffering from?
Your Answer:
Correct Answer: Acute rejection
Explanation:This patients is most likely experiencing an acute rejection. It is a cell mediated attack against the organ that has been transplanted. Antigens are either presented by blood borne cells with in the graft or antigen presenting cells in the body may be presenting class I and class II molecules that have been shed by the graft. Class I will activate CD8 and class II, CD4 cells, both of which will attack the graft.
Chronic rejection is a slow process which occurs months to years after the transplant. The exact mechanism is not very well understood but it probably involves a combination of Type III and Type IV hypersensitivity directed against the foreign MHC molecules which look like self-MHC presenting a foreign antigen.
Hyperacute Transplant Rejection occurs almost immediately and is often evident while you are still in surgery. It is caused by accidental ABO Blood type mismatching of the donor and recipient which almost never happens anymore. This means the host has preformed antibodies against the donated tissue. -
This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 11
Incorrect
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The passage of leukocytes through the wall of the blood vessels is best described by which of the following terms?
Your Answer:
Correct Answer: Diapedesis
Explanation:The steps involved in leukocyte arrival and function are:
1. margination: cells migrate from the centre to the periphery of the vessel
2. rolling: selectins are upregulated on the vessel walls
3. adhesion: upregulation of the adhesion molecules ICAM and VCAM on the endothelium interact with integrins on the leukocytes, interaction of these results in adhesion
4. diapedesis and chemotaxis: diapedesis is the transmigration of the leukocyte across the endothelium of the capillary and towards a chemotactic product
5. phagocytosis: engulfing the offending substance/cell. -
This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 12
Incorrect
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Painful erections along with deviation of the penis to one side when erect are seen in which of the following conditions?
Your Answer:
Correct Answer: Peyronie’s disease
Explanation:Peyronie’s disease leads to development of fibrous plaques in the penile soft tissue and occurs in 1% of men, most commonly affecting white males above 40 years age. It is a connective tissue disorder named after a French surgeon, François de la Peyronie who first described it. Symptoms include pain, hard lesions on the penis, abnormal curvature of erect penis, narrowing/shortening, painful sexual intercourse and in later stages, erectile dysfunction. 30% cases report fibrosis in other elastic tissues such as Dupuytren’s contractures of the hand. There is likely a genetic predisposition as increased incidence is noted among the male relatives of an affected individual.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 13
Incorrect
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The mechanism of action of streptokinase involves:
Your Answer:
Correct Answer: Direct conversion of plasminogen to plasmin
Explanation:Streptokinase is an enzyme that is produced by group A beta haemolytic streptococcus and is an effective and cost efficient method for the dissolution of a clot used in cases of MI and pulmonary embolism. It works by directly converting plasminogen to plasmin which breaks down the blood components in the clot and fibrin, dissolving the clot. Streptokinase is a bacterial product and thus the body will develop immunity against it.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 14
Incorrect
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A 59-year-old woman with hyperaldosteronism is prescribed a diuretic. Which of the following diuretics promotes diuresis by opposing the action of aldosterone?
Your Answer:
Correct Answer: Potassium-sparing diuretic
Explanation:The term potassium-sparing refers to an effect rather than a mechanism or location. Potassium-sparing diuretics act by either antagonising the action of aldosterone (spironolactone) or inhibiting Na+ reabsorption in the distal tubules (amiloride). This group of drugs is often used as adjunctive therapy, in combination with other drugs, for the management of chronic heart failure. Spironolactone, the first member of the class, is also used in the management of hyperaldosteronism (including Conn’s syndrome) and female hirsutism (due to additional antiandrogen actions).
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 15
Incorrect
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Which of the following clinical signs will be demonstrated in a case of Brown-Séquard syndrome due to hemisection of the spinal cord at mid-thoracic level?
Your Answer:
Correct Answer: Ipsilateral spastic paralysis, ipsilateral loss of vibration and proprioception (position sense) and contralateral loss of pain and temperature sensation beginning one or two segments below the lesion
Explanation:Brown–Séquard syndrome results due to lateral hemisection of the spinal cord and results in a loss of motricity (paralysis and ataxia) and sensation. The hemisection of the cord results in a lesion of each of the three main neural systems: the principal upper motor neurone pathway of the corticospinal tract, one or both dorsal columns and the spinothalamic tract. As a result of the injury to these three main brain pathways the patient will present with three lesions. The corticospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the upper motor neurons). The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense). The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion. At the lesion site, all sensory modalities are lost on the same side, and an ipsilateral flaccid paralysis.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 16
Incorrect
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A middle-aged man undergoes an upper gastrointestinal endoscope for a benign oesophageal stricture. During the procedure, he suffers an iatrogenic perforation at the site. Imaging shows a contained leak and a small amount of surgical emphysema. Which of the following is the most appropriate nutritional option?
Your Answer:
Correct Answer: Total parenteral nutrition
Explanation:Iatrogenic perforation of the gastrointestinal tract
related to diagnostic or therapeutic endoscopy is
a rare but severe adverse event, associated with
significant morbidity and mortalityConservative treatment may be suitable for patients with limited oesophageal injury and contained leakage. Such patients include those suffering endoscopic iatrogenic perforation, as the patient is likely to be fasted and the diagnosis made promptly. They must remain nil by mouth, with appropriate antibiotic cover, and proton pump inhibitor therapy, total parenteral nutrition, and continued observation. Similarly, medical treatment might be suitable for cases of inoperable malignant stricture, that is, palliation.
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This question is part of the following fields:
- Generic Surgical Topics
- Upper Gastrointestinal Surgery
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Question 17
Incorrect
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A 45-year old male, who was a chronic smoker presented to the clinic with backache and dry, incessant cough. On examination, he was found to have raised blood pressure, purplish striae on his abdomen, truncal obesity and tenderness over the lower thoracic spine. These findings are suggestive of which condition?
Your Answer:
Correct Answer: Small-cell anaplastic (oat cell) carcinoma
Explanation:The symptoms suggest Cushing syndrome due to increased glucocorticoid levels. One cause of Cushing syndrome is ectopic production of adrenocorticotrophic hormone from oat cell carcinoma. As oat cell carcinoma is known to be highly metastatic, the tenderness in lower back could represent metastatic involvement.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 18
Incorrect
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A 30 year old man presents with a surgical wound that is erythematous, tender and discharging pus. He states that he had undergone an inguinal hernia repair eight days earlier. What is the cause of this?
Your Answer:
Correct Answer: Infection with Staphylococcus aureus
Explanation:Answer: Infection with Staphylococcus aureus
Surgical site infections (SSIs) are among the most common healthcare-associated infections, and contribute significantly to patient morbidity and healthcare costs. Staphylococcus aureus is the most common microbial cause. The epidemiology of S. aureus is changing with the dissemination of newer clones and the emergence of mupirocin resistance. Pre-operative screening, using culture- or molecular-based methods, and subsequent decolonization of patients who are positive for methicillin-susceptible S. aureus and methicillin-resistant S. aureus (MRSA) reduces SSIs and hospital stay. This applies especially to major clean surgery, such as cardiothoracic and orthopaedic, involving the insertion of implanted devices. However, it requires a multi-disciplinary approach coupled with patient education. Universal decolonization pre-operatively without screening for S. aureus may compromise the capacity to monitor for the emergence of new clones of S. aureus, contribute to mupirocin resistance, and prevent the adjustment of surgical prophylaxis for MRSA (i.e. replacement of a beta-lactam agent with a glycopeptide or alternative).
A surgical site infection is an infection that occurs after surgery in the part of the body where the surgery took place. Surgical site infections can sometimes be superficial infections involving the skin only. Other surgical site infections are more serious and can involve tissues under the skin, organs, or implanted material.
Symptoms include:
Redness and pain around the area where you had surgery
Drainage of cloudy fluid from your surgical wound
Fever -
This question is part of the following fields:
- Clinical Microbiology
- Principles Of Surgery-in-General
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Question 19
Incorrect
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A 60 year old woman develops an enterocutaneous fistula which is high output following a recent stricturoplasty. Her medical history shows that she has been suffering from small bowel Crohn's disease for the past 17 years. A small bowel follow through shows it to be 14 cm from the DJ flexure and her overlying skin is becoming excoriated. What is the most appropriate course of action?
Your Answer:
Correct Answer: Commence TPN and octreotide
Explanation:Total parenteral nutrition (TPN) is usually indicated with suspected gastric, duodenal, or small-bowel fistula. When the fistula output is very high, discontinuance of oral intake is recommended because oral intake stimulates further losses of fluids, electrolytes, and protein via the fistula. A decrease in fistula output frequently occurs with the initiation of TPN.
Volume depletion from a proximal high-output fistula can be controlled with the use of the long-acting somatostatin analogue octreotide, which acts by inhibiting GI hormones. The administration of octreotide reportedly diminishes fistula output, but whether it shortens the time required for fistula closure remains to be determined.
Draus et al recommended a 3-day trial of octreotide, maintaining that if the fistula output is reduced during this time, then administration of the drug should be continued. Two meta-analyses showed that somatostatin and its analogues decreased the time for fistula closure and increased the closure rate. -
This question is part of the following fields:
- Generic Surgical Topics
- The Abdomen
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Question 20
Incorrect
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A 40 year old man suffered severe trauma following a MVA. His BP is 72/30 mmhg, heart rate of 142 beats/mins and very feeble pulse. He was transfused 3 units of blood and his BP returned to 100/70 and his heart rate slowed to 90 beats/min. What decreased after transfusion?
Your Answer:
Correct Answer: Total peripheral resistance
Explanation:The patient is in hypovolemic shock, he is transfused with blood, this fluid resuscitation will result in a decreased sympathetic discharge and adequate ventricular filling which will result in the decreases TPR with an increased CO and cardiac filling pressures
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 21
Incorrect
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A 55-year-old man is recovering following an elective right hemicolectomy for carcinoma of the caecum. His surgery is uncomplicated, when should oral intake resume?
Your Answer:
Correct Answer: Within 24 hours of surgery
Explanation:It has been well established that any delay in the resumption of normal oral diet after major surgery is associated with increased rates of infectious complications and delayed recovery. Early oral diet is safe 4 h after surgery in patients with a new non-diverted colorectal anastomosis. Some report that low residue diet, rather than a clear liquid diet, after colorectal surgery is associated with less nausea, faster return of bowel function, and a shorter hospital stay without increasing postoperative morbidity when administered in association with prevention of postoperative ileus. Spontaneous food intake rarely exceeds 1200–1500 kcal/day. To reach energy and protein requirements, additional oral nutritional supplements are useful.
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This question is part of the following fields:
- Post-operative Management And Critical Care
- Principles Of Surgery-in-General
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Question 22
Incorrect
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A 55-year old male type 2 diabetic is admitted to the vascular ward for a femoral-popliteal bypass. He suddenly develops expressive dysphasia and marked right-sided weakness. The Senior house officer arranges a CT head scan which shows a 60% left middle cerebral artery territory infarct. There are no beds on the stroke unit. Overnight the patient becomes unresponsive and a CT head confirms no bleed. What is the next best management option?
Your Answer:
Correct Answer: Hemicranieotomy
Explanation:In 1–10% of all patients with acute middle cerebral artery occlusion, the subsequent ischemic stroke can be classified as “malignant,” defined by ischemic brain tissue large enough to cause a considerable increase of ICP and potential cerebral herniation.
Clinically, the patients present with severe hemispheric symptoms including hemiparesis or hemiplegia, loss of visual field, gaze deviation and, depending on the affected hemisphere, neglect or aphasia. Patients may also show an impaired level of consciousness, nausea, vomiting, papillary changes and papilledema as signs of increased ICP.
Decompressive craniectomy is the only therapeutic approach that is based on data of large randomized controlled trials in this condition. Decompressive craniectomy reduces the mortality rate in these patients, however leaving the majority of patients with at least some disability. Other treatment options like osmotherapy may be used in an individual risk-benefit-assessment, but evidence for these treatments and procedures is scarce. -
This question is part of the following fields:
- Emergency Medicine And Management Of Trauma
- Principles Of Surgery-in-General
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Question 23
Incorrect
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A 39 year old man presents with dysphagia, which he has had for several years. Medical history shows that he has achalasia and has had numerous dilatations. Over the past month, his dysphagia has worsened. At endoscopy, a friable mass is noted in the oesophagus. What is the most likely diagnosis?
Your Answer:
Correct Answer: Squamous cell carcinoma
Explanation:Achalasia is a rare neurological deficit of the oesophagus that produces an impaired relaxation of the lower oesophageal sphincter and decreased motility of the oesophageal body. Achalasia is generally accepted to be a pre-malignant disorder, since, particularly in the mega-oesophagus, chronic irritation by foods and bacterial overgrowth may contribute to the development of dysplasia and carcinoma.
When oesophageal cancer develops in patients with underlying achalasia, diagnosis tends to be in the more advanced stages of cancer, compared to cases with no achalasia, because both physicians and patients often regard symptoms such as dysphagia and chest discomfort as attributable to the achalasia, rather than to other causes. Therefore, additional approaches that would lead to earlier diagnosis might be pursued less aggressively.
Achalasia is a predisposing factor for oesophageal squamous cell carcinoma. -
This question is part of the following fields:
- Generic Surgical Topics
- Upper Gastrointestinal Surgery
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Question 24
Incorrect
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Which of the following has the highest content of triglycerides?
Your Answer:
Correct Answer: Chylomicron
Explanation:Created by the small intestinal cells, chylomicrons are large lipoprotein molecules which transport lipids to the liver, adipose, cardiac and skeletal tissue. Chylomicrons are mainly composed of triglycerides (,85%) along with some cholesterol and cholesteryl esters. Apo B-48 is the main apolipoprotein content.
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 25
Incorrect
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A 70-year old man had had a large indirect inguinal hernia for 3 years. He presents at the out patient clinic complaining of pain in the scrotum. There is, however, no evidence of obstruction or inflammation. You conclude that the hernial sac is most probably compressing the:
Your Answer:
Correct Answer: Ilioinguinal nerve
Explanation:The ilioinguinal nerve arises together with the iliohypogastric nerve from the first lumbar nerve to emerge from the lateral border of the psoas major muscle just below the iliohypogastric and passing obliquely across the quadratus lumborum and iliacus muscles. It perforates the transversus abdominis, near the anterior part of the iliac crest and communicates with the iliohypogastric nerve between the internal oblique and the transversus. It then pierces the internal oblique to distribute filaments to it and accompanying the spermatic cord through the subcutaneous inguinal ring, is distributed to the skin of the upper and medial parts of the thigh, the skin over the root of the penis and the upper part of the scrotum in man and to the skin covering the mons pubis and labium majus in the woman. As the ilioinguinal nerve runs through the inguinal canal, it could easily be compressed by a hernial sac.
The femoral branch of genitofemoral nerve provides sensory innervation of the upper medial thigh.
The femoral nerve innervates the compartment of the thigh and also has some cutaneous sensory branches to the thigh.
The iliohypogastric nerve innervates the skin of the lower abdominal wall, upper hip and upper thigh. The subcostal nerve innervates the skin of the anterolateral abdominal wall and the anterior scrotal nerve is a terminal branch of the ilioinguinal nerve. -
This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 26
Incorrect
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An 26-year-old man sought admission due to persistent non-bloody diarrhoea. The patient is HIV-positive. Examination of stool sample showed numerous acid-fast cysts. Which of the following organism is the most likely cause of diarrhoea?
Your Answer:
Correct Answer: Cryptosporidium parvum
Explanation:Cryptosporidium parvum is one of several species that causes cryptosporidiosis, a parasitic disease of the mammalian intestinal tract. Primary symptoms of C. parvum infection are acute, watery, and non-bloody diarrhoea. C. parvum infection is of particular concern in immunocompromised patients, where diarrhoea can reach 10–15 l per day.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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Question 27
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:
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 28
Incorrect
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An old woman complains of a lack of sensation halfway down the anterior surface of the thigh. The cause of this:
Your Answer:
Correct Answer: Would result from damage to the nerve that innervates the pectineus muscle
Explanation:The pectineus is supplied by the second, third and fourth lumbar nerves through the femoral nerve and by the third lumbar through the accessory obturator when it exists. The anterior surface of the thigh receives its innervation from the femoral nerve as well, thus this is the nerve most likely to be injured
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This question is part of the following fields:
- Anatomy
- Basic Sciences
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Question 29
Incorrect
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Arterial blood gas analysis of a man admitted with acute exacerbation of chronic obstructive pulmonary disease (COPD) showed the following: pH = 7.28, p(CO2) = 65.5 mmHg, p(O2)= 60 mmHg and standard bicarbonate = 30.5 mmol/l. This patient had:
Your Answer:
Correct Answer: Respiratory acidosis
Explanation:Acidosis with high p(CO2) and normal standard bicarbonate indicates respiratory acidosis, commonly seen in acute worsening of COPD patients. Respiratory acidosis occurs due to alveolar hypoventilation which leads to increased arterial carbon dioxide concentration (p(CO2)). This in turn decreases the HCO3 –/p(CO2) and decreases pH. In acute respiratory acidosis, the p(CO2) is raised above the upper limit of normal (over 45 mm Hg) with a low pH. However, in chronic cases, the raised p(CO2) is accompanied with a normal or near-normal pH due to renal compensation and an increased serum bicarbonate (HCO3 – > 30 mmHg).
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This question is part of the following fields:
- Basic Sciences
- Physiology
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Question 30
Incorrect
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A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy. An emergency CT scan reveals a mass in the posterior fossa, with distortion of the lateral ventricles. After removing the tumour, the biopsy reveals it contains glial fibrillary acidic protein (GEAP). What's the most likely diagnosis?
Your Answer:
Correct Answer: Astrocytoma
Explanation:Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.
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This question is part of the following fields:
- Basic Sciences
- Pathology
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SESSION STATS - PERFORMANCE PER SPECIALTY
