Cellular Injury and Adaptation MCQs

## QUESTION 1 A 17-year-old boy infected with hepatitis A experiences mild nausea for about 1 week and develops very mild scleral icterus. On physical examination, he has minimal right upper quadrant tenderness. Laboratory findings include a serum AST of 68 U/L, ALT of 75 U/L, and total bilirubin of 5.1 mg/dL. The increase in this patient's serum enzyme levels most likely results from which of the following changes in the hepatocytes? A. Autophagy by lysosomes B. Clumping of nuclear chromatin C. Defects in the cell membrane D. Dispersion of ribosomes E. Swelling of the mitochondria **ANSWER: C** **Explanation:** Irreversible cell injury is associated with loss of membrane integrity. This allows intracellular enzymes to leak into the serum. All other morphologic changes listed are associated with reversible cell injury, in which the cell membrane remains intact. ## QUESTION 2 A 16-year-old boy sustained blunt trauma to the abdomen when the vehicle he was driving struck a bridge abutment at high speed. Peritoneal lavage shows a hemoperitoneum, and at laparotomy, a small portion of the left lobe of the liver is removed because of the injury. Several weeks later, a CT scan of the abdomen shows that the liver has nearly regained its size before the injury. Which of the following processes best explains this CT scan finding? A. Apoptosis B. Dysplasia C. Fatty change D. Hydropic change E. Hyperplasia F. Hypertrophy G. Metaplasia **ANSWER: E** **Explanation:** The liver is one of the few organs in the human body that can partially regenerate through hyperplasia.