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Question 1
Correct
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After a severe asthma attack, a 26-year-old woman is left in a markedly hypoxic state. In which of the following organs are the arterial beds most likely to be vasoconstricted due to the hypoxia?
Your Answer: Lungs
Explanation:Hypoxic pulmonary vasoconstriction is a local response to hypoxia resulting primarily from constriction of small muscular pulmonary arteries in response to reduced alveolar oxygen tension. This unique response of pulmonary arterioles results in a local adjustment of perfusion to ventilation. This means that if a bronchiole is obstructed, the lack of oxygen causes contraction of the pulmonary vascular smooth muscle in the corresponding area, shunting blood away from the hypoxic region to better-ventilated regions. The purpose of hypoxic pulmonary vasoconstriction is to distribute blood flow regionally to increase the overall efficiency of gas exchange between air and blood.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 2
Correct
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Where do the cells belonging to the mononuclear phagocyte system originate?
Your Answer: Bone marrow
Explanation:The macrophage originates from a committed bone marrow stem cell. It is called the pluripotent hematopoietic stem cell. This differentiates into a monoblast and then into a promonocyte and finally matures into a monocyte. When called upon they leave the bone marrow and enter into the circulation. Upon entering the tissue they transform into macrophages. Tissue macrophages include: Kupffer cells (liver), alveolar macrophages (lung), osteoclasts (bone), Langerhans cells (skin), microglial cells (central nervous system), and possibly the dendritic immunocytes of the dermis, spleen and lymph nodes.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 3
Incorrect
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Which of the following arteries, if ligated, will most likely affect blood supply to the pancreas?
Your Answer: Common hepatic
Correct Answer: Superior mesenteric
Explanation:The pancreas is a glandular organ in the body that produces important hormones such as insulin and glucagon. Its blood supply is from branches of the coeliac artery, superior mesenteric artery and the splenic artery. These are the arteries that if ligated, would affect blood supply to the pancreas.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 4
Correct
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Which of the following organs of the abdominal cavity is completely covered by the peritoneum?
Your Answer: Spleen
Explanation:Of the organs listed, the spleen is the only organ that is completely intraperitoneal, that is entirely in the peritoneum. Other completely intraperitoneal organs include the stomach, liver, appendix and the small intestines. The kidney, Inferior vena cava, aorta and the suprarenal glands are all retroperitoneal organs. The pancreas and the duodenum are partially retroperitoneal, with the tail of the pancreas in the peritoneum found in the splenorenal ligament while only the first part of the duodenum is intraperitoneal. For the intraperitoneal organs remember SALTD SPRSS
S = Stomach
A = Appendix
L = Liver
T = Transverse colon
D = Duodenum (only the 1st part)
S = Small intestines
P = Pancreas (only the tail)
R = Rectum (only the upper 3rd)
S = Sigmoid colon
S = Spleen
For retroperitoneal, just remember SADPUCKER:
S = suprarenal glands
A = Aorta and IVC
D = Duodenum (all but the 1st part)
P = Pancreas (all but the tail)
U = Ureter and bladder
C = Colon (ascending and descending)
K = Kidneys
E = Oesophagus
R = Rectum (Lower two-thirds)
For secondarily retroperitoneal remember ‘Pussy Cat Dolls“:
P = Pancreas
C = Colon (only ascending and descending)
D = Duodenum (only parts 2-4) -
This question is part of the following fields:
- Abdomen
- Anatomy
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Question 5
Correct
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A 20-year old cyclist falls off a speeding bike and fractures a structure that articulates with the tubercle of the 7th rib. Which structure is fractured?
Your Answer: Transverse process of vertebra T7
Explanation:A rib tubercle is a projection that is postero-inferior and lateral to the neck of a rib which articulates with the transverse process of the corresponding vertebra i.e. of the same number. Therefore, the tubercle of rib 7 articulates with the transverse process of T7 vertebra. The head of the rib 7, on the other hand, articulates with the 6th vertebra superiorly and the 7th vertebra inferiorly.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 6
Incorrect
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Which of the following associations is correctly matched with the body's defence mechanism in fighting infection?
Your Answer: First line of defence → neutrophils
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 7
Correct
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A 40-year-old woman is suspected to have an ovarian cancer. Which tumour marker should be requested to confirm the diagnosis?
Your Answer: CA-125
Explanation:CA-125 is a protein that is used as a tumour marker. This substance is found in high concentration in patients with ovarian cancer. It is the only tumour marker recommended for clinical use in the diagnosis and management of ovarian cancer.
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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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Which of the following is most likely to cause hypovolaemic hypernatremia:
Your Answer: Hyperalimentation
Explanation:Hypernatremia, characterised by a high serum sodium concentration, is rarely associated with volume overload (hypervolemia). A hypovolaemic hypernatremia may be seen during excessive administration of hypertonic sodium bicarbonate, hypertonic saline or hyperalimentation.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 9
Correct
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A 70-year old man who is suspected to have a perforated colonic diverticulum is explored in theatre through a midline incision. This incision will be through the:
Your Answer: Linea alba
Explanation:The linea alba is the point where this incision was made. It is a tendinous raphe in the midline of the abdomen extending between the xiphoid process and the symphysis pubis. It is placed between the medial borders of the recti and is formed by the blending of the aponeuroses of the external and internal obliques and transversi.
The linea aspera is a vertical ridge on the posterior surface of the femur.
The arcuate line is the inferior border of the posterior rectus sheath behind the rectus abdominis muscle.
The semilunar line is the lateral margin of the rectus abdominis.
The iliopectineal line is a line on the pelvic bones formed by the arcuate line of the ilium and the pectineal line of the pubis.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 10
Incorrect
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Calculate the cardiac stroke volume of a patient whose oxygen consumption (measured by analysis of mixed expired gas) is 300 ml/min, arterial O2 content is 20 ml/100 ml blood, pulmonary arterial O2 content is 15 ml/100 ml blood and heart rate is 60/min.
Your Answer: 10 ml
Correct Answer: 100 ml
Explanation:By Fick’s principle, VO2 = Q × (CA (O2) − CV (O2)) where VO2 = O2 consumption, Q = cardiac output and CA(O2) and CV(O2) are arterial and mixed venous O2 content respectively. Thus, in the given problem, 300 ml O2/min = Q × (20−15) ml O2/100 ml. Thus, Q = 6000 ml blood/min. Then, we can calculate stroke volume by dividing the cardiac output with heart rate. Thus, stroke volume = 6000 ml/min divided by 60/min stroke volume = 100 ml.
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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 50-year-old woman goes to the doctor complaining of myalgia, muscle cramps, and weakness; she is diagnosed with severe hypokalaemia. Which of the following is the most common cause of hypokalaemia?
Your Answer: Prolonged vomiting
Explanation:Potassium is one of the body’s major ions. Nearly 98% of the body’s potassium is intracellular. The ratio of intracellular to extracellular potassium is important in determining the cellular membrane potential. Small changes in the extracellular potassium level can have profound effects on the function of the cardiovascular and neuromuscular systems. Hypokalaemia may result from conditions as varied as renal or gastrointestinal (GI) losses, inadequate diet, transcellular shift (movement of potassium from serum into cells) and medications. The important causes of hypokalaemia are:
Renal losses: renal tubular acidosis, hyperaldosteronism, magnesium depletion, leukaemia (mechanism uncertain).
GI losses: vomiting or nasogastric suctioning, diarrhoea, enemas or laxative use, ileal loop.
Medication effects: diuretics (most common cause), β-adrenergic agonists, steroids, theophylline, aminoglycosides.
Transcellular shift: insulin, alkalosis.
Severe hypokalaemia, with serum potassium concentrations of 2.5–3 meq/l, may cause muscle weakness, myalgia, tremor, muscle cramps and constipation.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 12
Correct
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A patient with this condition has extracellular fluid volume expansion:
Your Answer: Nephrotic syndrome
Explanation:Nephrotic syndrome is a syndrome comprising of signs of nephrosis, including proteinuria, hypoalbuminemia, and oedema. It is a component of glomerulonephritis, in which different degrees of proteinuria occur. Essentially, loss of protein through the kidneys leads to low protein levels in the blood , which causes water to be drawn into soft tissues (oedema). Severe hypoalbuminemia can also cause a variety of secondary problems, such as water in the abdominal cavity (ascites), around the heart or lung (pericardial effusion, pleural effusion), high cholesterol, loss of molecules regulating coagulation (hence increased risk of thrombosis). The most common sign is excess fluid in the body due to the serum hypoalbuminemia. Lower serum oncotic pressure causes fluid to accumulate in the interstitial tissues. Sodium and water retention aggravates the oedema.
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This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
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Question 13
Incorrect
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A 12-year old girl was brought to the hospital with recurrent headaches for 6 months. Her physical examination revealed no abnormality. A CT scan of the head revealed a suprasellar mass with calcifications, eroding the surrounding sella turcica. The lesion is likely to represent:
Your Answer: Null cell adenoma
Correct Answer: Craniopharyngioma
Explanation:Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.
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This question is part of the following fields:
- Endocrine
- Pathology
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Question 14
Incorrect
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A middle aged man presented in OPD with a low grade fever and a persistent cough. His blood smear showed an increase in cells with large bi-lobed nuclei. Which of these cells represent the one seen on the smear?
Your Answer: Lymphocytes
Correct Answer: Monocytes
Explanation:Monocytes are white cells that protect the body against harmful pathogens. They are mobile and are produced in the bone marrow, mature there and circulate in the blood for about 1-3 days, where they enter the tissues and transform into macrophages. They are characteristically identified by their large bi-lobed nuclei.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 15
Correct
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In a hypertensive patient with secondary hyperaldosteronism, aldosterone is released mainly in response to:
Your Answer: Angiotensin II
Explanation:Secondary hyperaldosteronism in hypertension is either due to primary renin overproduction by the kidneys or renin overproduction secondary to decreased renal blood flow. The main stimulus for aldosterone release are adrenocorticotrophic hormone (ACTH), angiotensin II and high plasma K+ levels. Low plasma Na+ might also stimulate the adrenal cortex. Fluid overload will reduce aldosterone secretion. Atrial natriuretic peptide is secreted under conditions of expanded extracellular volume and will not lead to aldosterone secretion.
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This question is part of the following fields:
- Endocrinology
- Physiology
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Question 16
Correct
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A 50-year old gentleman who was admitted for elective surgery was found to have haemoglobin 9.5 g/dl, white blood cell count of 1.4 × 109/l and a mean corpuscular volume (MCV) of 134 fl. Which of the following is the likely finding on his peripheral blood smear?
Your Answer: Hypersegmented neutrophils
Explanation:The likely diagnosis is megaloblastic anaemia, which also shows the presence of hypersegmented neutrophils.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 17
Incorrect
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Which muscles are attached to the tibial tuberosity?
Your Answer: Adductor brevis
Correct Answer: Vastus intermedius
Explanation:The tuberosity of the tibia is the site of attachment to the ligamentum patella (the tendon of the quadriceps femoris muscle which include four heads: rectus femoris, vastus medialis, intermedius and lateralis).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 18
Incorrect
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A 20 year lady is brought to the A&E following a road accident. She is hypotensive and a CT scan of the abdomen reveals a shattered spleen. An emergency splenectomy is performed where the splenic artery is ligated right at its origin. Which of the following arteries will have a diminished blood flow owing to ligation of the splenic artery at its origin?
Your Answer: Coeliac
Correct Answer: Left gastroepiploic
Explanation:Ligation of the splenic artery right at its point of origin should cut off blood flow in its branches. The following are the branches of the splenic artery: pancreatic branches, short gastric branches and left gastroepiploic arteries.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 19
Incorrect
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A 24-year-old patient with recurrent episodes of deep vein thrombosis presents again to the clinic. Deficiency of which of the following blood proteins is the most probable cause of this episode?
Your Answer: Fibrinogen
Correct Answer: Antithrombin III
Explanation:Antithrombin III (ATIII) is a blood protein that acts by inhibiting blood coagulation by neutralizing the enzymatic activity of thrombin.
Antithrombin III deficiency is an autosomal dominant disorder that leads to an increased risk of venous and arterial thrombosis. Clinical manifestations typically appear in young adulthood.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 20
Correct
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A 39-year old female patient was diagnosed with a tumour of the left adrenal gland. The tumour, which is metastasizing to the adjacent tissues, has already extended to the left suprarenal vein. If the tumour is still spreading, which of the following veins will most likely be affected after the involvement of the left suprarenal vein?
Your Answer: Left renal vein
Explanation:The suprarenal veins or also known as the veins of Warshaw, are the veins that receive blood from the suprarenal glands. These veins receive blood from the medullary venous plexus and the cortex of the adrenal glands (suprarenal glands). They are two in number – the left and the right suprarenal veins. The right suprarenal vein drains into the inferior vena cava while the left suprarenal vein drains into the left renal vein. This therefore means that in the case of a metastasizing tumour involving the left suprarenal vein, the tumour will most likely extend from the left suprarenal vein to the left renal vein into which it drains.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 21
Correct
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Which one of the following groups of lymph nodes is most likely to be inflamed due to paronychia involving the big toe?
Your Answer: Vertical group of superficial inguinal lymph nodes
Explanation:Paronychia affecting the big toe will result in inflammation of the superficial inguinal lymph nodes as it drains lymph from the big toe.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 22
Incorrect
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An ultrasound report of a 35-year old female patient revealed that she had cancer of the pancreas and presented with subsequent severe obstructive jaundice. In which part of this was woman's pancreas was the tumour most likely located?
Your Answer: Uncinate process
Correct Answer: Head
Explanation:The pancreas is divided into five parts; the head, body, neck, tail, and the uncinate process. Of the five parts, tumours located at the head of the pancreas in most instances cause obstruction of the common bile duct more often than tumours in the other parts of the pancreas. This is because the common bile duct passes through the head of the pancreas from the gallbladder and the liver (it is formed where the cystic and the hepatic bile duct join) to empty bile into the duodenum. This biliary obstruction leads to accumulation of bile in the liver and a consequent bilirubinaemia (raised levels of blood bilirubin). This results in jaundice. The pancreas is not divided into lobes.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 23
Incorrect
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In a young, sexually active male, what is the most common cause of non-gonococcal urethritis?
Your Answer: Treponema
Correct Answer: Chlamydia
Explanation:Non-gonococcal urethritis is most commonly caused by Chlamydia trachomatis (50% cases). Less common organisms include Mycoplasma genitalium, Urea urealyticum and Trichomonas vaginalis. Chlamydia is also the commonest cause of non-gonococcal cervicitis in women and proctitis in both sexes.
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This question is part of the following fields:
- Pathology
- Renal
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Question 24
Incorrect
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A 24 year old mother is breastfeeding her first child. Which of the following cellular adaptations occurred in her breast tissue to allow her to do this?
Your Answer: Ductal epithelial metaplasia
Correct Answer: Lobular hyperplasia
Explanation:Under the influence of oestrogen in pregnancy, there is an increase in the number of lobules which will facilitate lactation.
Steatocytes occur due to loss of weight and nutritional deficit.
Metaplasia is a normal physiological process which is due to a change in normal epithelium with another type.
Lobular atrophy will result in a decreased capacity to provide milk.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Female Health
- Pathology
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Question 25
Incorrect
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A patient sustained an iatrogenic injury to one of the structures passing through the deep inguinal ring. This was during an operation to repair an inguinal hernia. Which structure is most likely to be injured?
Your Answer: Iliohypogastric nerve
Correct Answer: Round ligament of the uterus
Explanation:The deep inguinal ring transmits the spermatic cord in the man and the round ligament of the uterus in the female. It is bound below and medially by the inferior epigastric vessels (so these don’t go through it).
The ilioinguinal nerve, although it courses through the inguinal canal, does not pass through it.
The iliohypogastric nerves run between the internal oblique and transversus abdominis in the abdominal wall, piercing the internal oblique at the anterior superior iliac spine to travel just deep to the external oblique.
The inferior epigastric artery runs between the transversus abdominis and the peritoneum forming the lateral umbilical fold.
The medial umbilical ligament is the obliterated umbilical artery that it lies within the medial umbilical fold of peritoneum.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 26
Incorrect
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An ECG of a 30 year old woman revealed low voltage QRS complexes. This patient is most probably suffering from?
Your Answer: Thyrotoxicosis
Correct Answer: Pericardial effusion
Explanation:The QRS complex is associated with current that results in the contraction of both the ventricles. As ventricles have more muscle mass than the atria, they result in a greater deflection on the ECG. The normal duration of a QRS complex is 10s. A wide and deep Q wave depicts myocardial infarction. Abnormalities in the QRS complex maybe indicative of a bundle block, ventricular tachycardia or hypertrophy of the ventricles. Low voltage QRS complexes are characteristic of pericarditis or a pericardial effusion.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 27
Incorrect
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What principal artery that supplies the meninges is susceptible to rupture following trauma to the side of the head over the temporal region:
Your Answer: Posterior cerebral artery
Correct Answer: Middle meningeal artery
Explanation:The middle meningeal artery normally arises from the first or mandibular segment of the maxillary artery. The artery runs in a groove on the inside of the cranium, this can clearly be seen on a lateral skull X-ray. An injured middle meningeal artery is the most common cause of an epidural hematoma.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 28
Correct
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In relation to the muscles of facial expression, It is true to say:
Your Answer: They are in the same subcutaneous plane as the platysma muscle
Explanation:The facial muscles generally originate from the facial bones and attach to the skin, in the same plane as the platysma muscle. They are all innervated by cranial nerve VII (the facial nerve). The occipitofrontalis muscle consists of two parts: The occipital belly, near the occipital bone, and the frontal belly, near the frontal bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 29
Correct
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In a neurological exam on a robbery with violence victim, it was discovered that the victim had lost sense of touch to the skin over her cheek and chin (maxilla and mandible region). Where are the cell bodies of the nerve that is responsible for touch sensations of this region located?
Your Answer: Cranial nerve V ganglion
Explanation:The skin over the cheek and the maxilla are innervated by the trigeminal nerve (CN V). The trigeminal nerve has three major branches and it is the largest cranial nerve. The three branches of the trigeminal nerve are; the ophthalmic nerve, the maxillary nerve and the mandibular nerve. The trigeminal nerves ganglion is a sensory nerve ganglion know as the trigeminal ganglion (also referred to as the Gasser’s ganglion or the semilunar ganglion). It is contained in the dura matter in a cavity known as the Meckel’s cave, which covers the trigeminal impression near the apex of the petrous part of the temporal bone.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 30
Incorrect
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A young female in the 15th week of pregnancy presented to the emergency department with the passage of grape-like masses per vagina. Dilatation and curettage was done and microscopy revealed large avascular villi with trophoblastic proliferation. Which one of the following investigations is best recommended for her follow-up?
Your Answer:
Correct Answer: Serum β-hCG
Explanation:Trophoblast is the layer of cells surrounding the blastocyst and that later develops into the chorion and amnion. Gestational trophoblastic disease is a tumour arising from this trophoblast. It can occur during or after either an intrauterine or ectopic pregnancy. If it occurs in a pregnant woman, it usually leads to spontaneous abortion, eclampsia or fetal death. It can be either malignant or benign.
In suspected cases, investigations include measurement of serum beta subunit of human chorionic gonadotrophin (β-hCG) and pelvic ultrasound. Confirmatory test is a biopsy. Post-removal, the disease is classified clinically to assess further treatment. To assess the presence of metastases, further work-up includes computed tomography of the brain, chest, abdomen and pelvis. Chemotherapy is usually needed for persistent disease. If at least three consecutive, weekly serum β-hCG measurements are normal, treatment is considered successful. Follow-up is also done by measuring β-hCG.
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This question is part of the following fields:
- Pathology
- Women's Health
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SESSION STATS - PERFORMANCE PER SPECIALTY
