General Principles of Physiology Practice Test 2025 - Free Physiology Practice Questions and Study Guide

When blood pressure increases above normal levels, homeostatic mechanisms are activated to restore balance. The body has several systems in place that function to counteract such changes. Specifically, when there is an elevation in blood pressure, mechanisms such as vasodilation, increased excretion of sodium and water by the kidneys, and activation of certain hormones, including atrial natriuretic peptide (ANP), are triggered.

These responses work to lower blood pressure by widening blood vessels (vasodilation), which decreases the resistance the heart works against, and by increasing the volume of fluid being eliminated from the body, which reduces the overall blood volume. As a result, the body aims not only to return blood pressure to normal but may indeed lower it further to ensure stability. This is why overcompensation can be observed in the homeostatic response, as the mechanisms can overshoot the desired set point in their effort to stabilize blood pressure immediately after a significant rise.