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Question 1
Correct
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A 18-year old girl presents to her doctor with an excessively enlarged left breast as compared to the right breast since puberty. The most likely cause for this is:
Your Answer: Virginal breast hypertrophy
Explanation:Virginal breast hypertrophy’ is the term assigned to excessive growth of breasts during puberty and is a common phenomenon. It is also known as ‘juvenile macromastia’ or ‘ juvenile gigantomastia’. The breast hypertrophy often starts with menarche and occasionally occurs in growth spurts. These spurts can cause physical discomfort, red and itchy skin or pain in the breasts. The breasts can also grow continuously over several years and lead to overdevelopment of a normal breast. Nipples also undergo enlargement along with the breasts.
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This question is part of the following fields:
- Pathology
- Women's Health
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Question 2
Incorrect
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On exploration of an axillary wound, a branch from the third part of the axillary artery was found to be transected. Which of the following arteries would have been likely injured?
Your Answer: Lateral thoracic
Correct Answer: Anterior circumflex humeral
Explanation:The axillary artery gives off many branches from the first, second, or third parts along its course. The third part of the axillary artery gives off 3 branches: the subscapular, anterior and posterior circumflex humeral arteries.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 3
Correct
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The primary area involved in the pathology of Parkinson's disease is:
Your Answer: Substantia nigra
Explanation:Parkinson’s disease is a degenerative, movement disorder of the central nervous system, and is typically characterized by muscle rigidity, tremor and bradykinesia (in extreme cases, akinesia). Secondary symptoms include high-level cognitive dysfunction and subtle language problems.
Parkinson’s disease is also called ‘primary Parkinsonism’ or ‘idiopathic Parkinson’s disease and is the most common cause of Parkinsonism, a group of similar symptoms. The disorder is caused due to loss of pigmented dopaminergic cells in the pars compacta region of the substantia nigra.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 4
Incorrect
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Following a fracture in the fibula, an artery contained in a fibrous canal between tibialis posterior and flexor hallucis longus was lacerated. Which of the following arteries was injured?
Your Answer: Dorsalis pedis
Correct Answer: Peroneal
Explanation:The peroneal artery is deeply seated at the back of the fibular side of the leg, contained in a fibrous canal between the tibialis posterior and the flexor hallucis longus.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 5
Correct
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Fine-needle aspiration is a type of biopsy procedure. When performing a fine-needle aspiration of the lungs, which is the most common complication of the procedure?
Your Answer: Pneumothorax
Explanation:Pneumothorax is the most common complication of a fine-needle aspiration procedure. Various factors, such as lesion size, have been associated with increased risk of pneumothorax .
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 6
Correct
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Following a posterolateral thoracotomy, a surgeon may wish to infiltrate local anaesthetic above and below the incision to block the nerves supplying the thoracic wall. This wall is innervated by?
Your Answer: Intercostal nerves
Explanation:Intercostal nerves are the ventral primary rami of spinal nerves T1–T11. They give branches which supply the thoracic wall.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 7
Correct
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A 34-year-old woman has been suffering from headaches, fever, vomiting, and confusion for the last 5 days. A CT scan reveals an oedematous mass with ring enhancement in the left temporal region. It is biopsied, revealing glial cells, necrosis, neutrophils and lymphocytes. What is the most likely diagnosis?
Your Answer: Cerebral abscess
Explanation:A cerebral abscess can result from direct extension of cranial infections, penetrating head trauma, haematogenous spread, or for unknown causes. An abscess forms when an area of cerebral inflammation becomes necrotic and encapsulated by glial cells and fibroblasts. Oedema around the abscess can increase the intracranial pressure. Symptoms result from increased intracranial pressure and mass effects. It is most frequent in the third decade of life, and when it occurs in children, it is usually associated with congenital heart disease.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 8
Incorrect
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A 56 year old gentleman, who is a chronic smoker presents to the clinic with dyspnoea. His Chest X-ray shows intercostal space widening with increased blackening bilaterally. What is the most likely finding on his pulmonary function test?
Your Answer: Increased vital capacity
Correct Answer: Increased total lung capacity
Explanation:In patients suspected of having chronic obstructive pulmonary disease, pulmonary function testing (PFT) is useful to confirm airway obstruction, to quantify its severity and reversibility, for following disease progression and monitoring response to treatment. These tests include:
FEV1 – volume of air forcefully expired during the first second after a full breath
Forced vital capacity (FVC) – total volume of air expired with maximal force and flow-volume loops. The hallmark of airway obstruction is reduction of FEV1, FVC and the ratio of FEV1/FVC, with a concave pattern in expiratory tracing on the flow-volume loop. FEV1 and forced vital capacity (FVC) are easily measured with office spirometry and are useful to assess the severity of disease. Other parameters include increased total lung capacity, functional residual capacity and residual volume, which can help distinguish chronic obstructive pulmonary disease (COPD) from restrictive pulmonary disease where these values are lower than normal. Along with these, other tests are decreased vital capacity; and decreased diffusing capacity for carbon monoxide (DLCO). DLCO is non-specific and can be low in other disorders that affect the pulmonary vascular bed, such as interstitial lung disease. DLCO is however useful to distinguish COPD from asthma, in which DLCO is normal or elevated.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 9
Correct
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A patient is diagnosed with lung cancer. His physician told him that his lung cancer type is aggressive. It can grow rapidly and may undergo early metastasis, however it is very sensitive to chemotherapy and radiotherapy. Which lung cancer type is most likely present
Your Answer: Small-cell carcinoma
Explanation:Small-cell lung carcinoma (SCLC) is a type of highly malignant cancer that most commonly arises within the lung. SCLC usually metastasizes widely very early on in the natural history of the tumour, and in nearly all cases responds dramatically to chemotherapy and/or radiotherapy. Surgery has no role in the treatment of this disease.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 10
Correct
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Laboratory findings in a patient with dark urine and yellowish skin revealed a prolonged prothrombin time. Which of the following is the most likely cause of this finding?
Your Answer: Liver damage
Explanation:Various conditions may prolong the prothrombin time (PT), including: warfarin use, vitamin K deficiency, liver disease, disseminated intravascular coagulopathy, hypofibrinogenemia, heparin infusion, massive blood transfusion and hypothermia. Liver disease causes prolonging of PT due to diminished synthesis of clotting factors. Dark urine colour and jaundice are indicators of the presence of a liver disease in this patient.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 11
Correct
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The midgut loop, also called the primary intestinal loop in a developing embryo, is formed when the midgut bends around which of the following arteries?
Your Answer: Superior mesenteric
Explanation:In a developing foetus, the midgut develops to form most of the intestines. During this development process, the midgut usually bends around the superior mesenteric artery and forms what is referred to as the midgut loop.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 12
Correct
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An 18 -year-old female is diagnosed with folliculitis in the left axilla. What is the most likely organism that could cause this condition?
Your Answer: Staphylococcus aureus
Explanation:Folliculitis is the inflammation of the hair follicles. It is usually caused by Staphylococcus infection.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 13
Incorrect
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Causes of metabolic acidosis with a normal anion gap include:
Your Answer: Salicylate overdose
Correct Answer: Diarrhoea
Explanation:Excess acid intake and excess bicarbonate loss as in diarrhoea, are causes of metabolic acidosis with a normal anion gap. The other conditions all result in an increased anion gap.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 14
Correct
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A 76-year-old woman is diagnosed with diabetes mellitus after a urine test revealed she has glucosuria. Glucosuria may occur due to inadequate glucose reabsorption at:
Your Answer: Proximal convoluted tubule
Explanation:Glucose is reabsorbed almost 100% via sodium–glucose transport proteins (apical) and GLUT (basolateral) in the proximal convoluted tubule. Glycosuria or glucosuria is a condition of osmotic diuresis typical in those suffering from diabetes mellitus. Due to a lack of insulin, plasma glucose levels are above normal. This leads to saturation of receptors in the kidneys and glycosuria usually at plasma glucose levels above 11 mmol/l. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed renal glycosuria.
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This question is part of the following fields:
- Physiology
- Renal
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Question 15
Incorrect
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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: Hyperkalaemia
Correct 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:
- Fluids & Electrolytes
- Pathology
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Question 16
Correct
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A 13-year-old boy's mother notices he has a lump in his arm, near his right shoulder. An X-ray reveals a lateral projection in the metaphyseal region of his humerus. The lesion is removed and it is found to be composed of bony cortex, capped by cartilage. What's the most likely diagnosis in this case?
Your Answer: Osteochondroma
Explanation:Osteochondromas, or osteocartilaginous exostoses, are the most common benign bone tumours, and tend to appear near the ends of long bones. The overgrowth can occur in any bone where cartilage forms bone, and they are capped by cartilage. They are most common in people between the ages of 10-20 years old.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 17
Incorrect
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A 55-years-old man presented to the emergency department complaining of a squeezing sensation in his chest that has spread to his neck with associated worsening shortness of breath. Which of these laboratory tests would you ask for in this patient:
Your Answer: White blood cell count
Correct Answer: Creatine kinase-MB
Explanation:Creatine kinase-MB is a test that usually is ordered when the patient has chest pain as a cardiac marker. When a heart attack is suspected and a troponin test (which is more specific for heart damage), is not available CK-MB is ordered. There are 3 forms of CK: CK-MM, CK-BB and CK-MB. CK-MB is commonly found in heart tissue, therefore injured heart muscle cells release CK-MB into the blood. Elevated CK-MB levels indicate that it is probable that a person has recently had a heart attack.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 18
Correct
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Which ectopic tissue is usually contained in the Meckel's diverticulum?
Your Answer: Gastric
Explanation:The Meckel’s diverticulum is a vestigial remnant of the omphalomesenteric duct. This structure is also referred to as the vitelline and contains two types of ectopic tissue, namely; gastric and pancreatic.
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This question is part of the following fields:
- Anatomy
- Embryology
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Question 19
Correct
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Injury to this nerve will affect the function of the palatoglossus and levator veli palatini muscles:
Your Answer: Cranial nerve X
Explanation:The vagus nerve (cranial nerve X) innervates both the palatoglossus and levator veli palatini muscles.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 20
Correct
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The ability of the bacteria to cause disease or its virulence is related to :
Your Answer: Toxin and enzyme production
Explanation:The pathogenicity of an organism or its ability to cause disease is determined by its virulence factors. Many bacteria produce virulence factors that inhibit the host’s immune system. The virulence factors of bacteria are typically proteins or other molecules that are synthesized by enzymes. These proteins are coded for by genes in chromosomal DNA, bacteriophage DNA or plasmids. The proteins made by the bacteria can poison the host cells and cause tissue damage.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 21
Correct
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The muscle that stabilizes the stapes is innervated by which of the following nerves?
Your Answer: Facial nerve
Explanation:The stapedius is the smallest skeletal muscle in the human body. At just over one millimetre in length, its purpose is to stabilize the smallest bone in the body, the stapes and is innervated by a branch of the facial nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 22
Incorrect
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Calculate the pulmonary vascular resistance in an adult male with the following parameters:
Heart rate 70 beats/min
Arterial [O2] 0.24 ml O2/min
Venous [O2] 0.16 ml O2/mi
Whole body O2 consumption 500 ml/min
Pulmonary diastolic pressure 15 mmHg
Pulmonary systolic pressure 25 mmHg
Wedge pressure 5 mmHg.Your Answer: 1.5 resistance units (mmHg/l per min)
Correct Answer: 2.0 resistance units (mmHg/l per min)
Explanation:Pulmonary vascular resistance (PVR) = (Mean pulmonary artery pressure – Pulmonary capillary wedge pressure) divided by Cardiac output. To get cardiac output, Fick’s principle needs to be applied which states that VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CA = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24–0.16, CO = 500/0.8, CO = 6.25 l/min. To calculate mean pulmonary artery pressure, we use the formula: Mean pulmonary artery pressure = Diastolic pressure + 1/3(Systolic pressure – Diastolic pressure). Thus, Mean pulmonary artery pressure = 15 + 1/3(25 – 15) = 15 + 3. 33 = 18.33. Substituting these values in the first formula, PVR = 18.3–5/6.25 = 13.5/5.25 = 2.0 resistance units (mmHg/l per min) approximately.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 23
Correct
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During an OSCE exam a medical student is asked to locate the sternal angle. The sternal angle is a land mark for locating the level of the:
Your Answer: Second costal cartilage
Explanation:The sternal angle, a key landmark used in the clinic for auscultating for heart sounds, is the point of attachment of the costal cartilage of rib 2 to the sternum. It thus corresponds to the location of the second rib. A horizontal plane through the sternal angle traverses the T4/T5 intervertebral disc and marks the inferior boundary of the superior mediastinum.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 24
Correct
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A 25 year-old male patient was brought to the hospital due to a vehicular accident. A skull x-ray was done which revealed a fracture along the base of the middle cranial fossa. The patient has no sense of touch over the skin over his cheek and chin. Injury to the maxillary and the mandibular nerves is suspected. In which foramina do these two affected sensory branches leave the cranial cavity.
Your Answer: Foramen rotundum and foramen ovale
Explanation:The patient’s clinical manifestations suggests an injury to the maxillary and mandibular nerves. The maxillary branch (V2) of the trigeminal nerve (CN V) passes through and exits the skull via the pterygopalatine fossa and the foramen rotundum. At the base of the skull the foramen ovale (Latin: oval window) is one of the larger of the several holes (the foramina) that transmit nerves through the skull. The foramen ovale is situated in the posterior part of the sphenoid bone, posterolateral to the foramen rotundum. The following structures pass through foramen ovale: mandibular nerve, motor root of the trigeminal nerve, accessory meningeal artery (small meningeal or paradural branch, sometimes derived from the middle meningeal artery), lesser petrosal nerve, a branch of the glossopharyngeal nerve and an emissary vein connecting the cavernous sinus with the pterygoid plexus of veins. Occasionally it will also carry the anterior trunk of the middle meningeal vein.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 25
Incorrect
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Which Statement is true of the brachial plexus?
Your Answer: The suprascapular nerve is a branch of the lower trunk
Correct Answer: The posterior cord continues as the axillary nerve
Explanation:The lateral cord continues as the musculocutaeous nerve.
The medial cord continues as the ulnar nerve.
The posterior cord continues as the radial nerve and the axillary nerve.
The nerve to subclavius muscle is a branch of the C6 root.
The suprascapular nerve is a branch from the upper trunk.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 26
Correct
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A 4-year-old child was brought to a paediatrician for consult due to a palpable mass in his abdomen. The child has poor appetite and regularly complains of abdominal pain. The child was worked up and diagnosed with a tumour. What is the most likely diagnosis ?
Your Answer: Nephroblastoma
Explanation:Nephroblastoma is also known as Wilms’ tumour. It is a cancer of the kidneys that typically occurs in children. The median age of diagnose is approximately 3.5 years. With the current treatment, approximately 80-90% of children with Wilms’ tumour survive.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 27
Correct
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A 23-year-old woman decides to donate a kidney through a kidney chain. Which of the following indices would be expected to be decreased in the donor after full recovery from the operation?
Your Answer: Creatinine clearance
Explanation:Since medication to prevent rejection is so effective, donors do not need to be similar to their recipient. Most donated kidneys come from deceased donors; however, the utilisation of living donors is on the rise. Most problems encountered with live donation are associated with the donor. Firstly, there are the potentially harmful investigative procedures carried out in the assessment phase, the most hazardous being renal angiography, where there is cannulation of the artery and injection of a radio-opaque dye to determine the blood supply to the kidney. Secondly, there are the short-term risks of nephrectomy surgery. According to the literature, there is a mortality rate of between 1 in 1600 and 1 in 3000, but this is no more than is associated with any anaesthetic. In the initial postoperative period creatinine clearance may be decreased but this recovers fully over a few weeks to months. Long-term complications include prolonged wound pain.
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This question is part of the following fields:
- Physiology
- Renal
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Question 28
Incorrect
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A 50-year-old gentleman was recently diagnosed with hypertension, with no other abnormalities on physical examination. Further investigations revealed the following :
Na+ 144 mmol/l
K+ 3.0 mmol/l
Cl- 107 mmol/l
Bicarbonate 25 mmol/l.
Blood glucose 5.8 mmol/l.
What is the likely diagnosis?Your Answer: Renal artery stenosis
Correct Answer: Conn syndrome
Explanation:Overproduction of aldosterone (a mineralocorticoid) by the adrenal glands is known as Conn’s syndrome. It can be either due to an aldosterone-secreting adrenal adenoma (50-60% cases) or adrenal gland hyperplasia (40-50% cases). Excess aldosterone leads to sodium and water retention, along with potassium excretion. This leads to arterial (non-essential) hypertension. Conn’s syndrome is the commonest cause of primary hyperaldosteronism. Other symptoms include muscle cramps, headache (due to hypokalaemia) and metabolic alkalosis, which occurs due to increased secretion of H+ ions by the kidney. The raised pH of the blood traps calcium leading to symptoms of hypocalcaemia, which can be mimicked by liquorice ingestion and Liddle syndrome. To diagnose Conn’s syndrome, the ratio of renin and aldosterone is measured. Due to suppression of renin secretion, there is low renin to aldosterone ratio (<0.05). However, anti-hypertensives may affect the test results and should be withdrawn for 6 weeks. Computed tomography can also be done to detect the presence of adrenal adenoma. Cushing’s syndrome does not cause hypokalaemia with normal serum glucose levels. Nelson’s syndrome refers to increased ACTH secretion due to pituitary adenoma. Pheochromocytoma will not lead to hypokalaemia even though hypertension can be seen.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 29
Incorrect
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A sudden loud sound is more likely to result in cochlear damage than a slowly developing loud sound. This is because:
Your Answer: A sudden sound carries more energy
Correct Answer: There is a latent period before the attenuation reflex can occur
Explanation:On transmission of a loud sound into the central nervous system, an attenuation reflex occurs after a latent period of 40-80 ms. This reflex contracts the two muscles that pull malleus and stapes closer, developing a high degree of rigidity in the entire ossicular chain. This reduces the ossicular conduction of low frequency sounds to the cochlea by 30-40 decibels. In this way, the cochlea is protected from damage due to loud sounds (these are low frequency sounds) when they develop slowly.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 30
Incorrect
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A 10-year-old boy was sent for an x-ray of the leg because he was complaining of pain and swelling. The x-ray showed the classic sign of Codman's triangle. What is the most likely diagnosis of this patient?
Your Answer: Chondrosarcoma
Correct Answer: Osteosarcoma
Explanation:Codman’s triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. The main causes for this sign are osteosarcoma, Ewing’s sarcoma, eumycetoma, and a subperiosteal abscess.
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This question is part of the following fields:
- Neoplasia
- Pathology
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