How does the renal system help the body compensate for shock?

• A. By releasing adrenaline into the bloodstream
• B. By decreasing the amount of fluid excreted from the blood
• C. By storing excessive glycogen from the bloodstream
• D. By increasing systemic vascular resistance in the arteries

Answer: (B)

In shock, the kidneys help maintain circulating volume by conserving fluid. When perfusion to the kidneys drops, they respond by reducing urine production. Hormonal actions from the renin-angiotensin-aldosterone system and antidiuretic hormone promote sodium and water reabsorption, so less fluid is excreted in the urine. This fluid preservation helps keep blood volume up and supports blood pressure, aiding perfusion of vital organs.

Adrenaline release is part of the broader fight-or-flight response and causes systemic effects like vasoconstriction and increased heart rate, but it’s not the kidney’s direct mechanism for compensating shock. Storing excessive glycogen isn’t a renal function relevant to shock. Increasing systemic vascular resistance is a vascular response, not the kidney’s primary action.