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Question 1
Incorrect
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Diuretics that act on the ascending limb of the loop of Henle produce:
Your Answer: Reduced absorption of water
Correct Answer: Reduced active transport of sodium
Explanation:The loop of Henlé leads from the proximal convoluted tubule to the distal convoluted tubule. Its primary function uses a counter current multiplier mechanism in the medulla to reabsorb water and ions from the urine. It can be divided into four parts:
1. Descending limb of loop of Henlé – low permeability to ions and urea, while being highly permeable to water
2. Thin ascending limb of loop of Henlé – not permeable to water, but it is permeable to ions
3. Medullary thick ascending limb of loop of Henlé – sodium (Na+), potassium (K+) and chloride (Cl–) ions are reabsorbed by active transport. K+ is passively transported along its concentration gradient through a K+ channel in the basolateral aspect of the cells, back into the lumen of the ascending limb.
4. The cortical thick ascending limb – the site of action where loop diuretics such as furosemide block the K+/Na+/2Cl− co-transporters = reduced active transport.
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This question is part of the following fields:
- Physiology
- Renal
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Question 2
Incorrect
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Which of the following associations is correctly matched with the body's defence mechanism in fighting infection?
Your Answer: Non-specific cellular mechanism → B lymphocytes
Correct Answer: Specific cellular mechanism → cytotoxic T cells
Explanation:The immune system has certain levels of defence against pathogens. First line includes simple barriers such as skin, mucosa and stomach acid that prevent the pathogen from entering into the body. If this barrier is breached then the innate immune system is activated which includes leukocytes (macrophages, neutrophils, mast cells, eosinophils, basophils, natural killer cells). If the pathogens invade the second layer of defence then the third layer, adaptive immunity is activated, which includes B and T lymphocytes. B cells provide a humoral response whereas cytotoxic T cells have specific cellular mechanisms. They maintain a memory of past infections and are activated faster following a recurrence.
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This question is part of the following fields:
- General
- Physiology
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Question 3
Incorrect
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After surgery, a patient developed a stitch granuloma . Which leukocyte in the peripheral blood will become an activated macrophage in this granuloma?
Your Answer: Lymphocyte
Correct Answer: Monocyte
Explanation:Monocytes are leukocytes that protect the body against infections and move to the site of infection within 8-12 hours to deal with it. They are produced in the bone marrow and shortly after being produced are released into the blood stream where they circulate until an infection is detected. When called upon they leave the circulation and transform into macrophages within the tissue fluid and thus gain the capability to phagocytose the offending substance. Monocyte count is part of a complete blood picture. Monocytosis is the state of excess monocytes in the peripheral blood and may be indicative of various disease states. Examples of processes that can increase a monocyte count include: • chronic inflammation • stress response • hyperadrenocorticism • immune-mediated disease • pyogranulomatous disease • necrosis • red cell regeneration.
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This question is part of the following fields:
- General
- Physiology
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Question 4
Incorrect
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Which of the following is the most abundant WBC seen in a smear from a healthy person.
Your Answer: Monocytes
Correct Answer: Neutrophils
Explanation:neutrophils are the most abundant cell type of the WBC. These phagocytes are found normally in the blood and increase in number are seen during an acute inflammation. These the percentages of WBC in blood Neutrophils: 40 to 60%
Lymphocytes: 20 to 40%
Monocytes: 2 to 8%
Eosinophils: 1 to 4%
Basophils: 0.5 to 1%
Band (young neutrophil): 0 to 3%. eosinophils, basophils, neutrophils are known as granulocytes and monocytes and lymphocytes as agranulocytes.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 5
Incorrect
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Where is factor VIII predominantly synthesised?
Your Answer: Hepatocytes
Correct Answer: Vascular endothelium
Explanation:Factor VIII is an important part of the coagulation cascade. Deficiency causes haemophilia A. It is synthesised predominantly by the vascular endothelium and is not affected by liver disease. In the circulation it is bound to von Willebrand factor and it forms a stable complex with it. It is activated by thrombin or factor Xa and acts as a co factor to factor IXa to activate factor X which is a co factor to factor Va. Thrombin cleaves fibrinogen in fibrin and forms a meshwork to trap RBC and platelets to form a clot.
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This question is part of the following fields:
- General
- Physiology
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Question 6
Incorrect
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A 65-year old patient with altered bowl movement experienced the worsening of shortness of breath and exertional chest pains over the course of 8 weeks. Examination shows pallor and jugular venous distension. Furthermore, a test of the stool for occult blood is positive. Laboratory studies show:
Haemoglobin 7.4 g/dl
Mean corpuscular volume 70 fl Leukocyte count 5400/mm3
Platelet count 580 000/mm3 Erythrocyte sedimentation 33 mm/h
A blood smear shows hypochromic, microcytic RBCs with moderate poikilocytosis. Which of the following is the most likely diagnosis?Your Answer: Amyloidosis
Correct Answer: Iron deficiency anaemia
Explanation:Iron deficiency anaemia is the most common type of anaemia. It can occur due to deficiency of iron due to decreased intake or due to faulty absorption. An MCV less than 80 will indicated iron deficiency anaemia. On the smear the RBC will be microcytic hypochromic and will also show piokilocytosis. iron profiles tests are important to make a diagnosis. Clinically the patient will be pale and lethargic.
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This question is part of the following fields:
- General
- Physiology
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Question 7
Incorrect
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In a study, breast lumps were analysed to determine the characteristic of malignant neoplasm on biopsy. What microscopic findings are suggestive of malignancy?
Your Answer: Pleomorphism
Correct Answer: Invasion
Explanation:Invasion is suggestive of malignancy and an even better option would have been metastasis. Pleomorphism is found in both benign and malignant neoplasms along with atypia and anaplasia. A height nuclear/cytoplasmic ratio is suggestive of malignancy but not the best indicator. Malignant tumours are aggressive and growth rapidly. Necrosis can be seen in benign tumours if they deplete their blood supply.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 8
Correct
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A 65-year old man, known with Type 2 diabetes and chronic renal failure, is likely to eventually present with which of the following conditions?
Your Answer: Secondary hyperparathyroidism
Explanation:When the parathyroid glands secrete excess parathyroid hormone (PTH) in response to hypocalcaemia, it is known as Secondary hyperparathyroidism and is often seen in patients with renal failure. In chronic renal failure, the kidneys fail to excrete adequate phosphorus and also fail to convert enough vitamin D to its active form. This leads to formation of insoluble calcium phosphate in the body which ultimately causes hypocalcaemia. The glands then undergo hyperplasia and hypertrophy leading to secondary hyperparathyroidism. Symptoms include bone and joint pains, along with limb deformities. The raised PTH also results in pleiotropic effects on blood, the immune system and nervous system.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 9
Incorrect
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After having donated a unit of blood. The blood bank will prefer to use which of the following anticoagulants to store the blood?
Your Answer: Oxalate
Correct Answer: Citrate
Explanation:Calcium is necessary for coagulation to occur. Citrate being a chelator and combining with calcium ions to form un-ionised compound will prevent coagulation. Following transfusion the citrate is removed by the liver with in a few minutes. Oxalate also works on the same principle but it is toxic to the body.
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This question is part of the following fields:
- General
- Physiology
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Question 10
Incorrect
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A victim of road traffic accident presented to the emergency department with a blood pressure of 120/90 mm Hg, with a drop in systolic pressure to 100 mm Hg on inhalation. This is known as:
Your Answer: Pulsus bisferiens
Correct Answer: Pulsus paradoxus
Explanation:Weakening of pulse with inhalation and strengthening with exhalation is known as pulsus paradoxus. This represents an exaggeration of the normal variation of the pulse in relation to respiration. It indicates conditions such as cardiac tamponade and lung disease. The paradox refers to the auscultation of extra cardiac beats on inspiration, as compared to the pulse. Due to a decrease in blood pressure, the radial pulse becomes impalpable along with an increase in jugular venous pressure height (Kussmaul sign). Normal systolic blood pressure variation (with respiration) is considered to be >10 mmHg. It is >100 mmHg in Pulsus paradoxus. It is also predictive of the severity of cardiac tamponade.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 11
Correct
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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: 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
- Upper Limb
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Question 12
Incorrect
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Which nodes are most likely to be enlarged in a patient complaining of a boil located on the labia majora?
Your Answer: Deep inguinal
Correct Answer: Superficial inguinal
Explanation:The perineum, external genitalia, the labia majora and scrotum drain to the superficial inguinal lymph nodes. In a man, the testes do not drain to the superficial inguinal lymph nodes but rather travel in the spermatic cord and drain into the lumbar nodes. The lumbar nodes drain the internal pelvic organs. The sacral nodes drain the prostrate gland, uterus, vagina, rectum and posterior pelvic wall and the external iliac nodes in turn drain the lower limb. The internal iliac nodes drain the pelvis and gluteal region.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 13
Incorrect
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Out of the following options, which malignancy has the highest potential for multicentricity?
Your Answer: Adenocarcinoma of prostate
Correct Answer: Transitional cell carcinoma
Explanation:Transitional cell carcinomas can arise anywhere in the urothelium lining the urinary tract; and hence are known to be multicentric and recur commonly. Prostatic adenocarcinoma most commonly involves the posterior lobe of the prostate gland. Although renal cell carcinomas occasionally show multicentricity, it is not common. Penile carcinomas are usually locally infiltrative lesions. Wilm’s tumours are usually solitary, but can be bilateral or multicentric in 10% cases. Small cell carcinoma of lung and teratomas are usually solitary.
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This question is part of the following fields:
- Pathology
- Renal
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Question 14
Incorrect
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Which of the following muscles attaches to the pterygomandibular raphe?
Your Answer: Medial pterygoid muscle
Correct Answer: Superior pharyngeal constrictor muscle
Explanation:The pterygomandibular raphé (pterygomandibular ligament) provides attachment on its posterior border to the superior pharyngeal constrictor and on its anterior border to the buccinator muscle.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 15
Incorrect
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What percentage of the cardiac output is delivered to the brain?
Your Answer: 35%
Correct Answer: 15%
Explanation:Among all body organs, the brain is most susceptible to ischaemia. Comprising of only 2.5% of total body weight, the brain receives 15% of the cardiac output. Oxygen extraction is also higher with venous oxygen levels approximating 13 vol%, and arteriovenous oxygen difference of 7 vol%.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 16
Incorrect
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What is expected from complete transection of the inferior gluteal nerve when it emerges from the greater sciatic foramen?
Your Answer: The adductor part of the adductor magnus muscle would be affected
Correct Answer: Extension of the thigh would be the action most affected
Explanation:As the inferior gluteal nerve emerges from the greater sciatic foramen below the piriformis muscle, it divides into branches and enters the gluteus maximus muscle which extends the femur and bends the thigh in line with the body.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 17
Incorrect
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During a laparoscopic inguinal hernia repair, the surgeon finds an artery in the extraperitoneal connective tissue (preperitoneal fat) that courses vertically and just medial to the bowel as the bowel passes through the abdominal wall. Which artery is this?
Your Answer:
Correct Answer: Inferior epigastric
Explanation:The inferior epigastric artery comes from the external iliac artery just above the inguinal ligament to curve forward in the subperitoneal tissue and then ascend obliquely along the medial margin of the deep inguinal ring. It continues to ascend between the rectus abdominis and the posterior lamella of its sheath after piercing the fascia transversalis and passing anterior to the linea semicircularis. Finally it gives off numerous branches that anastomose above the umbilicus with the superior epigastric branch of the internal mammary artery and with the lower intercostal arteries. As this artery ascends obliquely upwards from its origin it lies along the lower medial margins of the deep inguinal ring and posterior to the start of the spermatic cord. It is found in the preperitoneal fat of the abdomen lying just superficial to the peritoneum and forms the lateral umbilical fold. Hernias that pass lateral to this are indirect and medial to this, direct hernias.
The deep circumflex artery travels along the iliac crest on the inner surface of the abdominal wall. It is very lateral to the abdominal wall and hernias would pass medial to it.
The superficial circumflex iliac, superficial epigastric, superficial external pudendal arteries are all superficial arteries found in the superficial fascia.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 18
Incorrect
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For calculation of cardiac output by Fick's principle, which of the following vessels is the best source of venous blood to determine the arterial-to-venous oxygen tension difference?
Your Answer:
Correct Answer: Pulmonary artery
Explanation:Fick’s principle states that the total uptake (or release) of a substance by peripheral tissues is equal to the product of the blood flow to the peripheral tissues and the arterial– venous concentration difference (gradient) of the substance. It is used to measure the cardiac output, and the formula is Cardiac output = oxygen consumption divided by arteriovenous oxygen difference. Assuming there are no shunts across the pulmonary system, the pulmonary blood flow equals the systemic blood flow. The arterial and venous blood oxygen content is measured by sampling from the pulmonary artery (low oxygen content) and pulmonary vein (high oxygen content). Peripheral arterial blood is used as a surrogate for the pulmonary vein.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 19
Incorrect
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A patient is diagnosed with Conn’s syndrome. Aldosterone is secreted from where?
Your Answer:
Correct Answer: Zona glomerulosa of the adrenal cortex
Explanation:The adrenal gland comprises an outer cortex and an inner medulla, which represent two developmentally and functionally independent endocrine glands.
The adrenal medulla secretes adrenaline (70%) and noradrenaline (30%)
The adrenal cortex consists of three layers (remembered by the mnemonic GFR):
G = zona glomerulosa – secretes aldosterone
F = zona fasciculata – secretes cortisol and sex steroids
R = zona reticularis – secretes cortisol and sex steroids.
Aldosterone facilitates the reabsorption of sodium and water and the excretion of potassium and hydrogen ions from the distal convoluted tubule and collecting ducts. Conn’s syndrome is characterized by increased aldosterone secretion from the adrenal glands.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 20
Incorrect
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An episiotomy is indicated for a woman during a difficult vaginal delivery. Whilst the registrar was performing this procedure she made a median cut too far through the perineal body cutting the structure immediately posterior. Which structure is this?
Your Answer:
Correct Answer: External anal sphincter
Explanation:An episiotomy is an incision that is made whenever there is a risk of a tear during vaginal deliver. A posterolateral incision, as opposed to a median incision is preferred. Of the options given, the external anal sphincter lies right posterior to the perineal body. The sacrospinous and the sacrotuberous ligaments are deep in the perineum that they should not be involved in this.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 21
Incorrect
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A 27 year-old male patient was admitted to the hospital due to recurrent fever for the past 2 weeks. The patient claimed that he is an intravenous drug user. Following work up, the patient was diagnosed with infective endocarditis. Which is the most likely organism responsible for this diagnosis?
Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:Acute bacterial endocarditis is a fulminant illness lasting over days to weeks (<2weeks). It is most likely due to Staphylococcus aureus especially in intravenous drug abusers.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 22
Incorrect
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A 15-day old male baby was brought to the emergency department with sweating and his lips turning blue while feeding. He was born full term. On examination, his temperature was 37.9°C, blood pressure 75/45 mmHg, pulse was 175/min, and respiratory rate was 42/min. A harsh systolic ejection murmur could be heard at the left upper sternal border. X-ray chest showed small, boot-shaped heart with decreased pulmonary vascular markings. He most likely has:
Your Answer:
Correct Answer: Tetralogy of Fallot
Explanation:The most common congenital cyanotic heart disease and the most common cause of blue baby syndrome, Tetralogy of Fallot shows four cardiac malformations occurring together. These are ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), overriding aorta (degree of which is variable), and right ventricular hypertrophy. The primary determinant of severity of disease is the degree of pulmonary stenosis. Tetralogy of Fallot is seen in 3-6 per 10,000 births and is responsible for 5-7% congenital heart defects, with slightly higher incidence in males. It has also been associated with chromosome 22 deletions and DiGeorge syndrome. It gives rise to right-to-left shunt leading to poor oxygenation of blood. Primary symptom is low oxygen saturation in the blood with or without cyanosis at birth of within first year of life. Affected children ay develop acute severe cyanosis or ‘tet spells’ (sudden, marked increase in cyanosis, with syncope, and may result in hypoxic brain injury and death). Other symptoms include heart murmur, failure to gain weight, poor development, clubbing, dyspnoea on exertion and polycythaemia. Chest X-ray reveals characteristic coeur-en-sabot (boot-shaped) appearance of the heart. Treatment consists of immediate care for cyanotic spells and Blalock–Taussig shunt (BT shunt) followed by corrective surgery.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 23
Incorrect
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Which of the following will be a seen in a patient with a plasma thyroid-stimulating hormone (TSH) level of 14 mU/l (normal < 5 mU/l) and a low T3 resin uptake of 19% (normal 25–35%)?
Your Answer:
Correct Answer: Periorbital swelling and lethargy
Explanation:Low T3 resin uptake combined with raised TSH is indicative of hypothyroidism. Signs and symptoms include dull expression, facial puffiness, lethargy, periorbital swelling due to infiltration with mucopolysaccharides, bradycardia and cold intolerance. Anxiety, palpitations, tachycardia, raised body temperature, heat intolerance and weight loss are all seen in hyperthyroidism.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 24
Incorrect
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In the human body, veins often run a course parallel to the artery that has the same name. Which of the following listed veins doesn't run parallel to the artery of the same name?
Your Answer:
Correct Answer: Inferior mesenteric
Explanation:The inferior mesenteric artery and inferior mesenteric vein don’t run in tandem because the vein is part of the portal venous system-draining into the splenic vein which drains into the hepatic portal vein. The inferior mesenteric artery is a branch of the descending aorta at the level of L3. The inferior mesenteric vein and artery, however, drain the same region i.e. the descending and sigmoid colon and rectum.
Superior epigastric vessels course together and are the continuation of the internal thoracic artery and vein.
Superficial circumflex iliac vessels course together in the superficial fat of the abdominal wall.
Superior rectal vessels are the terminal ends of the inferior mesenteric vessels, located on the posterior surface of the rectum.
The ileocolic artery and vein are branches off the superior mesenteric vessels. Both course in the mesentery, supplying/draining the caecum, appendix, terminal portion of the ileum. The inferior epigastric vessels run together.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 25
Incorrect
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Which organ is most vulnerable to haemorrhagic shock?
Your Answer:
Correct Answer: Kidneys
Explanation:At rest, the brain receives 15% cardiac output, muscles 15%, gastrointestinal tract 30% and kidneys receive 20%. However, if normalised by weight, the largest specific blood flow is received by the kidneys at rest (400 ml/min x 100g), making them highly vulnerable in the case of a haemorrhagic shock.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 26
Incorrect
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During an inguinal hernia repair, an incision is made parallel to and 5cm above the inguinal ligament. The registrar is warned to look out for the inferior epigastric vessels to avoid damage. Between which layers of the abdominal wall is the registrar likely to find these vessels?
Your Answer:
Correct Answer: Transversus abdominis muscle and peritoneum
Explanation:The inferior epigastric vessels lie on the inner surface of the transversus abdominis muscle covered by the parietal peritoneum. This layer of peritoneum lies over the inferior epigastric vessels to make the lateral umbilical fold. Camper’s and Scarpa’s fascia are two layers of the superficial fascia, the fatty layer and the membranous layer respectively.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 27
Incorrect
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The posterior cord contains nerve fibres from which of the following levels of the spinal cord?
Your Answer:
Correct Answer: C5, C6, C7, C8 and T1
Explanation:THE correct answer is A. The posterior cord derives its fibres from the spinal nerves C5,C6,C7,C8,T1. This cord is formed from the fusion of the posterior divisions of the upper, lower, and middle trunks.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 28
Incorrect
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What is the name of the cutaneous branch of the posterior primary ramus of C2?
Your Answer:
Correct Answer: Greater occipital nerve
Explanation:The dorsal primary ramus of the spinal nerve C2 is the greater occipital nerve which provides cutaneous innervation to the skin of the back of the head. The ventral primary ramus gives off the great auricular nerve, the lesser occipital nerve and the ansa cervicalis.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 29
Incorrect
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The renal tubule is the portion of the nephron that contains the fluid that has been filtered by the glomerulus. Which of the following substances is actively secreted into the renal tubules?
Your Answer:
Correct Answer: Potassium
Explanation:The renal corpuscle filters out solutes from the blood, delivering water and small solutes to the renal tubule for modification. In normal circumstances more than 90% of the filtered load of K is reabsorbed by the proximal tubules and loops of Henlé and almost all K appearing in the urine has been secreted by the late distal tubules and collecting tubules. So the rate of excretion is usually independent of the rate of filtration, but is closely tied to the rate of secretion and control of K excretion, largely accomplished by control of the secretion rate. Around 65–70% of the filtered potassium is reabsorbed along with water in the proximal tubule and the concentration of potassium in the tubular fluid varies little from that of the plasma.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 30
Incorrect
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A surgeon performing a laparoscopic repair of an inguinal hernia visualizes a loop of bowel protruding through the abdominal wall to form a direct inguinal hernia. When this is viewed from the side of the abdomen with a laparoscope, in which region would the hernial sac be?
Your Answer:
Correct Answer: Medial inguinal fossa
Explanation:In a direct inguinal hernia, visceral contents exit the abdomen through a weak point in the fascia in the medial inguinal fossa i.e. the area between the medial and lateral umbilical folds. Such a hernia doesn’t pass through the deep inguinal ring or the lateral inguinal fossa. Note that direct hernias can go through the superficial inguinal ring, although rarely. The supravesical fossa, between the median and medial umbilical folds, is formed by a peritoneal reflection from the anterior abdominal wall onto the bladder and the retrovesical fossa is the region behind the urinary bladder.
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This question is part of the following fields:
- Abdomen
- Anatomy
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SESSION STATS - PERFORMANCE PER SPECIALTY
