Anatomy and Physiology II Practice Test 2026 - Free Anatomy Practice Questions and Study Guide

The kidneys play a crucial role in fluid retention and balance within the body. They are responsible for filtering the blood and regulating the levels of various substances, including water, electrolytes, and waste products. Through processes like filtration and reabsorption, the kidneys can adjust the volume and concentration of urine produced, which helps maintain homeostasis in terms of fluid balance.

The kidneys are also involved in regulating blood pressure by managing the volume of blood through fluid retention or excretion. This regulation is essential for ensuring that the body's tissues receive an adequate supply of blood and that fluids do not accumulate excessively in the body, leading to conditions like edema. In contrast, while the liver, stomach, and lungs have important functions in digestion and gas exchange, they are not primarily responsible for the intricate balance of fluids in the body like the kidneys.