Inadequate tissue perfusion leading to sustained cellular hypoxia is associated with which cellular dysfunction?

• A. Overactive sodium pump
• B. Increased mitochondrial activity
• C. Dysfunctional sodium pump
• D. Enhanced glycolysis

Answer: (C)

When tissue perfusion is inadequate, oxygen delivery drops and cells rely more on anaerobic glycolysis, causing ATP production to fall. Many cellular processes that require ATP slow or stop, especially the Na+/K+ ATPase pump that keeps intracellular sodium low and potassium high. With ATP unavailable, this pump fails, sodium accumulates inside the cell and water follows by osmosis, leading to cell swelling and loss of membrane integrity. This dysfunction of the sodium pump under hypoxic stress is a hallmark of sustained cellular hypoxia. Other options don’t fit because overactivity of the pump isn’t sustainable without ATP, mitochondria can’t increase activity in low-oxygen conditions, and enhanced glycolysis is a compensatory response rather than a dysfunction.