When the Arterial Blood Pressure Declines to 70/50 Mm Hg

Question

When the arterial blood pressure declines to 70/50 mm Hg,
A) GFR decreases.
B) diuresis occurs.
C) aldosterone secretion decreases.
D) ADH secretion diminishes.

Accepted Answer

When arterial blood pressure declines to 70/50 mm Hg, the GFR (glomerular filtration rate) decreases due to decreased blood flow to the kidneys. This is a compensatory mechanism to maintain blood pressure and prevent further loss of fluid through urine. Diuresis (increased urine output) would not occur at this low blood pressure as the body attempts to conserve fluid. Aldosterone secretion would increase in response to low blood pressure in an attempt to retain sodium and water, while ADH (antidiuretic hormone) secretion would increase to promote water retention. Therefore, choices B, C, and D are not the best answer.