A 45-year-old woman presents with acute onset of right upper quadrant pain and jaundice. Liver biopsy shows hepatocytes with diffuse cytoplasmic clearing and cell swelling without nuclear changes. This is the earliest morphological manifestation of reversible cell injury. Which mechanism is primarily responsible for this finding?
- A Accumulation of triglyceride within the cytoplasm
- B Failure of the Na+/K+ ATPase pump leading to sodium and water influx ✓
- C Detachment of ribosomes from the rough endoplasmic reticulum
- D Activation of caspases causing cytoskeletal degradation
Correct answer: B. Failure of the Na+/K+ ATPase pump leading to sodium and water influx
Explanation
Cellular swelling (hydropic change) is the earliest reversible injury, caused by failure of ATP-dependent Na+/K+ ATPase pumps. Sodium accumulates intracellularly, drawing in water. Triglyceride accumulation (fatty change) occurs later with more severe injury. Ribosomal detachment and caspase activation are not the primary mechanisms of simple cellular swelling.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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