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Question 1
Correct
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Which muscle would be affected most following injury to the transverse cervical artery?
Your Answer: Trapezius
Explanation:The latissimus dorsi receives blood from the thoracodorsal artery, the supraspinatus receives its blood from the suprascapular artery, the levator scapulae and the rhomboids are supplied by the dorsal scapular artery and the transverse cervical artery supplies blood to the trapezius.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 2
Correct
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A patient under went repair of a lingual artery aneurysm in the floor of the mouth. During surgical dissection from the inside of the mouth which muscle would you have to pass through to reach the main portion of the lingual artery?
Your Answer: Hyoglossus
Explanation:The lingual artery first runs obliquely upward and medialward to the greater horns of the hyoid bone. It then curves downward and forward, forming a loop which is crossed by the hypoglossal nerve, and passing beneath the digastric muscle and stylohyoid muscle it runs horizontally forward, beneath the hyoglossus, and finally, ascending almost perpendicularly to the tongue, turns forward on its lower surface as far as the tip, to become the deep lingual artery.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 3
Correct
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A 45-year old farmer was referred to the surgical clinic with complaints of pain in his right hypochondrium. Investigations confirmed the diagnosis of hepatocellular carcinoma with malignant ascites. According to you, what is the most likely cause of HCC in this patient?
Your Answer: Aflatoxin
Explanation:Aflatoxins are naturally occurring toxins produced by the Aspergillus fungus (most often, A. flavus and A. parasiticus). These organisms are common and their native habitat is soil, decaying vegetation and grains. They can contaminate the grain before harvest or after storage, more likely in high-humidity (at least 7%) or high temperature environment of after stressful conditions like drought. Aflatoxins are mycotoxins and also carcinogenic. They get metabolized in the liver to an epoxide, aflatoxin M1. High exposure can lead to acute necrosis, cirrhosis or liver carcinoma. These substances can cause haemorrhage, acute liver damage, oedema, and alteration in digestion, absorption and/or metabolism of nutrients. Although humans are susceptible to these toxins like all other animals, they have a high tolerance level and hence, rarely develop acute aflatoxicosis. However, children are particularly susceptible to exposure leading to growth impairment and delayed development. Chronic exposure carries a high risk of hepatic cancer, due to intercalation of its metabolite aflatoxin M1 into the DNA and alkylation of the bases because of its epoxide moiety.
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This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
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Question 4
Correct
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A lesion involving the lateral portion of the dorsal columns at the level of the nape of the neck will most likely affect:
Your Answer: Vibratory sensations from the ipsilateral arm
Explanation:At the level mentioned in the question, the lateral portion of dorsal columns comprises of the fasciculus cuneatus. Axons carrying the sensations of touch, vibration and proprioception from the ipsilateral arm enter the spinal cord and ascend in the fasciculus cuneatus, synapsing in the nucleus cuneatus of the caudal medulla. Secondary neurons from this nucleus give rise to internal arcuate fibres, which decussate and ascend to the thalamus as the medial lemniscus. Tertiary neurons from there project to the ipsilateral somatosensory cortex. Thus, any damage to the fasciculus cuneatus will result in a deficit in tactile, proprioceptive and vibratory sensations in the ipsilateral arm, and not the contralateral arm.
Fine motor control of the fingers is mainly carried by the ipsilateral lateral corticospinal tract in the lateral funiculus of the cord. Motor control of the contralateral foot is carried by the ipsilateral corticospinal tract in the lateral funiculus of the cord. Lack of sweating of the face could be produced by interruption of sympathetic innervation. Proprioception from the ipsilateral leg is carried by the fasciculus gracilis in the medial part of the dorsal columns.
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This question is part of the following fields:
- Neurology
- Physiology
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Question 5
Correct
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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: 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 6
Correct
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The histological exam of a tuberculous granuloma shows a periphery of multinuclear giant cells, with a central area of:
Your Answer: Caseous necrosis
Explanation:Granulomas with necrosis tend to have an infectious cause. The chronic infective lesion in this case typically presents with a central area of caseous (cheese-like) necrosis. Foam cells are the fat-laden M2 macrophages seen in atherosclerosis
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This question is part of the following fields:
- Cell Injury & Wound Healing; Dermatology
- Pathology
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Question 7
Correct
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The gastrosplenic ligament also known as the gastrolienal ligament is the structure that connects the greater curvature of the stomach to the hilum of the spleen. Which of the following arteries would most likely be injured if a surgeon accidentally tore this ligament?
Your Answer: Short gastric
Explanation:The short gastric arteries arise from the end of the splenic arteries and form five to seven branches. The short gastric arteries inside the gastrosplenic ligament from the left to the right, supply the greater curvature of the stomach. The hepatic artery proper runs inside the hepatoduodenal ligament. The right gastric artery and the left gastric artery are contained in the hepatogastric ligament. The caudal pancreatic artery branches off from the splenic artery and supplies the tail of the pancreas. The middle colic artery supplies the transverse colon. The splenic artery does not travel in the gastrosplenic ligament and so it would not be damaged by a tear to this ligament.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 8
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 9
Correct
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A chloride sweat test was performed on a 13-year-old boy. Results indicated a high likelihood of cystic fibrosis. This diagnosis is associated with a higher risk of developing which of the following?
Your Answer: Bronchiectasis
Explanation:Cystic fibrosis is a life-threatening disorder that causes the build up of thick mucus in the lungs, digestive tract, and other areas of the body. It is a hereditary autosomal-recessive disease caused by mutations of the CFTR gene. Cystic fibrosis eventually results in bronchiectasis which is defined as a permanent dilatation and obstruction of bronchi or bronchioles.
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This question is part of the following fields:
- Pathology
- Respiratory
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Question 10
Correct
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Which of the following will be a likely sequelae of complete ileal resection?
Your Answer: Vitamin B12 deficiency
Explanation:The ileum is a part of the small intestine and has a pH of around 7-8 (neutral or slightly alkaline). Its main function is absorption of products of digestion. The ileal wall has multiple villi, which in turn have numerous microvilli. This increases the surface area available for absorption significantly. The cells lining the ileum contain multiple enzymes such as protease and carbohydrase, which aid in the final stages of digestion. Villi contain lacteals which absorb the products of fat digestion, fatty acids and glycerol. Thus, ileal resection will lead to their decreased absorption and increased fat content in the stool. The ileum is also responsible for absorption of vitamin B12.
Maximum water absorption occurs in the colon followed by the jejunum. Hence, ileal resection is less likely to lead to fluid volume deficiency. Also, most minerals (like calcium, iron etc.) are absorbed in the duodenum, and thus will not be affected by ileal resection.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 11
Correct
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Injury to which of the following arteries is likely to affect the blood supply to the seminal vesicles?
Your Answer: Middle rectal
Explanation:Ligation of middle rectal artery is most likely to affect the blood supply of seminal vesicles since arteries supplying the seminal vesicles are derived from the middle and inferior vesical and middle rectal arteries.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 12
Correct
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A butcher accidentally cut himself on his right index finger. Which of the following substances when in contact with the basement membrane of the injured vasculature will activate the coagulation cascade as well as the kinin system in a first response to this injury?
Your Answer: Hageman factor
Explanation:Hageman factor/factor XII in the intrinsic pathway activates prekallikrein and factor XI. Deficiency will not cause excessive bleeding as other coagulation factors will be utilized but the PTT will be greater than 200 seconds.
Thromboxane promotes platelet aggregation and causes vasoconstriction.
Plasmin, which is cleaved from plasminogen acts as an anticoagulant which breaks down thrombi.
Platelet activating factor promotes platelet aggregation and is also chemotactic to neutrophils.
Histamine acts as a vasodilator.
Platelet inhibiting factor acts an anticoagulant.
Renin is a hormone released from the kidney that causes vasoconstriction and water retention.
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This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
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Question 13
Correct
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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: 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 14
Correct
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the action of the semimembranosus muscle is:
Your Answer: Extension of the hip and flexion of the knee
Explanation:the semimembranosus is situated at the back and medial side of the thigh. It arises from the upper and outer impression on the tuberosity of the ischium, above and lateral to the biceps femoris and semitendinosus. It is inserted mainly into the horizontal groove on the posterior medial aspect of the medial condyle of the tibia. it flexes the knee and assists in extension of the hip.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 15
Correct
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Which of the following arteries, that runs on the superior aspect of the first part of the duodenum, forms the lower boundary of the epiploic foramen (also known as the foramen of Winslow)?
Your Answer: Hepatic
Explanation:The epiploic foramen is an important anatomical opening that allows for the communication between the greater peritoneal sac and the lesser peritoneal sac. Its boundaries are formed; superiorly by the caudate lobe of the liver, anteriorly by the hepatoduodenal ligament (containing the components of the portal triad), inferiorly by the first part of the duodenum and posteriorly by the peritoneum covering the inferior vena cava. The superior aspect of the first part of the duodenum, which forms the inferior boundary of the foramen of Winslow, forms the course of the hepatic artery before it ascends to the porta hepatis where it divides into its right and left branches.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 16
Correct
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Post-total gastrectomy, there will be a decreased production of which of the following enzymes?
Your Answer: Pepsin
Explanation:Pepsin is a protease that is released from the gastric chief cells and acts to degrade proteins into peptides. Released as pepsinogen, it is activated by hydrochloric acid and into pepsin itself. Gastrin and the vagus nerve trigger the release of pepsinogen and HCl when a meal is ingested. Pepsin functions optimally in an acidic environment, especially at a pH of 2.
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This question is part of the following fields:
- Gastroenterology
- Physiology
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Question 17
Correct
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Extracellular body fluid as compared with intracellular body fluid:
Your Answer: Is relatively rich in glucose
Explanation:The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. Ensuring the right amount of body water is part of fluid balance, an aspect of homeostasis. The extracellular fluid (ECF) includes all fluids outside the cells. This fluid can be divided into three fluid departments: interstitial (in the tissue spaces) fluid, blood plasma and lymph, and specialised compartments called transcellular fluid. The extracellular fluid surrounds all the cells in the body and is in equilibrium with the intracellular fluid. So, its composition must remain fairly constant even though substances are passing into and out of the cells. The interstitial fluid, though called a fluid, is in a reality a gel-like composition made up of: water, proteoglycan molecules and collagen. The extracellular fluid constitutes 40% of total body water, with intracellular fluid making up the remaining 60%. It is relatively rich in glucose.
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This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
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Question 18
Correct
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Identify which of the following muscles acts on two joints?
Your Answer: Sartorius
Explanation:The sartorius muscle, the longest muscle in the body, is one of the two jointed or biarticular muscles. It originates from the anterior superior iliac spine and part of the notch between the anterior superior iliac spine and anterior inferior iliac spine and crosses both the hip joint and the knee joint. At the hip joint the sartorius flexes and rotates the thigh at the hip joint and flexes the leg at the knee joint.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 19
Correct
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A 35 year-old man presents with high grade fever for 7 days after returning from a trip to India. He tested positive for widal test. What is the most likely organism that caused his fever?
Your Answer: Salmonella typhi
Explanation:Typhoid fever is caused by virulent bacteria called Salmonella typhi. Salmonella typhi spread through contaminated food or water and occasionally through direct contact with someone who is infected.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 20
Correct
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Choose the most correct answer regarding the obturator internus muscle.
Your Answer: It emerges from the pelvis through the lesser sciatic foramen
Explanation:The obturator internus arises from the inner surface of the anterolateral wall of the pelvis and the pelvic surface of the obturator membrane. The fibres converge rapidly towards the lesser sciatic foramen and end in four or five tendinous bands and leave the pelvis through the lesser sciatic foramen.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 21
Correct
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Anthrax is an infection caused by the bacterium Bacillus anthracis. Anthrax spores have been used as a biological warfare weapon. What is the drug of choice in treating anthrax infection?
Your Answer: Ciprofloxacin
Explanation:Early antibiotic treatment of anthrax is essential. A delay may significantly lessen the chances for survival of the patient. Treatment for anthrax infection include large doses of intravenous and oral antibiotics, such as fluoroquinolones (ciprofloxacin), doxycycline, erythromycin, vancomycin, or penicillin.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 22
Correct
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A chef, whilst preparing food, cut her thumb with a knife. She transected the arteria princeps pollicis. This artery is a branch of the?
Your Answer: Radial artery
Explanation:The radial artery branches into the arteria princeps pollicis as it turns medially into the deep part of the hand. The arteria princeps pollicis is distributed to the skin and subcutaneous tissue of the thumb.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 23
Correct
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A teenage Somalian boy presents with a complaint of an enlarged lower jaw. His blood film shows blast cells and macrophages. Which virus is responsible for this?
Your Answer: Epstein–Barr virus
Explanation:Burkitt’s lymphoma is a type of non-Hodgkin’s lymphoma. Histologically it is characterised by a starry sky appearance due to numerous neoplastic macrophages which are required to clear the rapidly dividing tumour cells/blast cells. Burkitt’s lymphoma commonly affects the jaw bone, forming a huge tumour mass. It is associated with translocation of c-myc gene and has three types: 1) endemic/African type, 2)sporadic and 3)immunodeficiency-associated. The first type is strongly associated with EBV.
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This question is part of the following fields:
- General
- Physiology
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Question 24
Correct
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Purkinje fibres in the heart conduct action potentials at the rate of:
Your Answer: 1.5–4.0 m/s
Explanation:Purkinje fibres control the heart rate along with the sinoatrial node (SA node) and the atrioventricular node (AV node). The QRS complex is associated with the impulse passing through the Purkinje fibres. These fibres conduct action potential about six times faster than the velocity in normal cardiac muscle.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 25
Correct
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A 30-year-old woman known with Von Willebrand disease (vWD) has to undergo surgery. Which of these complications is most unlikely in this patient?
Your Answer: Hemarthrosis
Explanation:Von Willebrand disease (vWD) is an inherited haemorrhagic disorder characterised by the impairment of primary haemostasis. It is caused by the deficiency or dysfunction of a protein named von Willebrand factor. The most common manifestation due to the condition is abnormal bleeding. Complications include easy bruising, hematomas, epistaxis, menorrhagia, prolonged bleeding and severe haemorrhage. Hemarthrosis is a complication that is more commonly found in haemophilia.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 26
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 27
Correct
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A 13 year old girl presented with signs of shortness of breath, chest pain, non-productive cough, oedema of the lower extremities and cyanosis of the fingertips. She has a history of a ventricular septal defect not surgically corrected. The most probable cause of these symptoms is:
Your Answer: Shunt reversal
Explanation:A ventricular septal defect (VSD) is a common form of congenital heart defects and is characterised by the presence of a hole in the wall that separates the right from the left ventricle. Medium or large defects can cause many complications. One of these complication is Eisenmenger syndrome, characterised by reversal of the shunt (from left-to-right shunt into a right-to-left) ,cyanosis and pulmonary hypertension.
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This question is part of the following fields:
- Cardiovascular
- Pathology
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Question 28
Correct
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A 70 year old women, died suddenly. She had a history of hypertension and aortic stenosis. On autopsy her heart weighed 550g. What is the most likely cause of this pathology?
Your Answer: Hypertrophy
Explanation:Due to increased pressure on the heart as a result of hypertension and aortic stenosis, the myocardial fibres hypertrophied to adapt to the increased pressure and to effectively circulate blood around the body. Hyperplasia could not occur, as myocardial fibres are stable cells and cannot divide further.
Fat does not deposit in the heart due to volume overload.
Myocardial oedema is not characteristic of a myocardial injury.
Metaplasia is a change in the type of epithelium.
Atrophy would result in a decreased heart size and inability to function.
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This question is part of the following fields:
- Cell Injury & Wound Healing; Cardiovascular
- Pathology
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Question 29
Incorrect
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After a cerebral infarction, which of these histopathogical findings is most likely to be found?
Your Answer: Gangrenous necrosis
Correct Answer: Liquefactive necrosis
Explanation:The brain has a high lipid content and typically undergoes liquefaction with ischaemic injury, because it contains little connective tissue but high amounts of digestive enzymes.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 30
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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