Cell injury MCQs — Past Paper OmpathStudy

Cell Injury MCQs — Questions and Answers This paper contains 55 questions recovered from all 34 source pages. 1. A 48-year-old woman has a malignant lymphoma involving lymph nodes in the para-aortic region. She is treated with a chemotherapeutic agent which results in the loss of neoplastic cells through fragmentation of individual cell nuclei and cytoplasm. Over the next 2 months, the lymphoma decreases in size, as documented on abdominal CT scans. By which of the following mechanisms has her neoplasm primarily responded to therapy? A. Coagulative necrosis B. Mitochondrial poisoning C. Phagocytosis D. Acute inflammation E. Apoptosis Answer: E. The induction of individual cell death occurs in the process of apoptosis. The drug effect is targeted primarily at the neoplastic cells, not normal cells. 2. A 53-year-old man has had severe chest pain for the past 6 hours. On physical examination he is afebrile, but has tachycardia. Laboratory studies show a serum troponin I of 10 ng/mL. A coronary angiogram is performed emergently and reveals 90% occlusion of the anterior interventricular (left anterior descending) artery. In this setting, an irreversible injury to myocardial fibers will have occurred when which of the following cellular changes occurs? A. Glycogen stores are depleted B. Cytoplasmic sodium increases C. Nuclei undergo karyorrhexis D. Intracellular pH diminishes E. Blebs form on cell membranes Answer: C. Chromatin clumping is reversible, but dissolution of the entire nucleus is not, and when the nucleus is lost, the cell will die. An acute coronary syndrome with myocardial infarction is described here. 3. While in a home improvement center warehouse buying paint, a 35-year-old man hears 'Look out below!' and is then struck on the leg by a falling pallet rack, which strikes him on his left leg in the region of his thigh. The skin is not broken. Within 2 days there is a 5 x 7 cm purple colour to the site of injury. Which of the following substances has most likely accumulated at the site of injury to produce a yellow-brown colour at the site of injury 16 days later? A. Lipofuscin B. Bilirubin C. Melanin D. Hemosiderin E. Glycogen Answer: D. The iron in the heme pigment from the red blood cells in the hemorrhage beneath the skin is incorporated into hemosiderin granules that impart the yellow to brown colour of the healing contusion (bruise) from blunt force trauma. 4. A 54-year-old man with a chronic cough has a squamous cell carcinoma diagnosed in his right lung. While performing a pneumonectomy, the thoracic surgeon notes that the hilar lymph nodes are small, 0.5 to 1.0 cm in size, and jet black in colour throughout. Which of the following is the most likely cause for this appearance to the hilar nodes? A. Anthracotic pigment B. Lipochrome deposits C. Melanin accumulation D. Hemosiderosis E. Metastatic carcinoma Answer: A. The black colour comes from carbon pigments in dust particles inhaled over the years, engulfed by macrophages, and sent via lymphatics to the lymph nodes. It looks bad but does not compromise lung function. Smokers will have more anthracosis. 5. A 50-year-old woman with a history of unstable angina suffers an acute myocardial infarction. Thrombolytic therapy with tissue plasminogen activator (tPA) is administered to restore coronary blood flow. In spite of this therapy, the extent of myocardial fiber injury may increase because of which of the following cellular abnormalities? A. Cytoskeletal intermediate filament loss B. Decreased intracellular pH from anaerobic glycolysis C. Increased free radical formation D. Mitochondrial swelling E. Nuclear chromatin clumping F. Reduced protein synthesis Answer: C. Such toxic oxygen radicals are released from neutrophils when blood flow is restored following ischemia. This is a reperfusion injury. Overall, there is likely to be more good than harm to restoration of blood flow. 6. A 12-year-old boy has had multiple episodes of ear pain accompanied by fever. On examination his right tympanic membrane is red and bulging with yellow exudate. Laboratory studies of the exudate show culture positive for Hemophilus influenzae. A year later he has conductive hearing loss on the right, and a head CT scan shows a mass in the right middle ear. Which of the following materials is most likely to be seen in the tissue curetted from his middle ear? A. Lipofuscin pigment B. Russell bodies C. Neutrophil granules D. Cholesterol crystals E. Anthracotic pigment Answer: D. An inflammatory mass persisted, with cellular necrosis, and the lipid from the cell membranes is broken down and cholesterol crystals form. The boy has the complication of otitis media known as a cholesteatoma 7. A 43-year-old man has complained of mild burning substernal pain following meals for the past 3 years. Upper GI endoscopy is performed and biopsies are taken of an erythematous area of the lower esophageal mucosa 3 cm above the gastroesophageal junction. There is no mass lesion, no ulce