Which body system regulates the water, electrolyte, and pH balance of blood?

The urinary system is responsible for regulating water, electrolyte, and pH balance in the blood through several key functions. It accomplishes this by filtering blood to form urine, which contains waste products, excess salts, and water that the body does not need. The kidneys, as part of the urinary system, play a crucial role in maintaining homeostasis by adjusting the volume and concentration of urine produced based on the body's hydration status and electrolyte levels.

When there is an excess of water or electrolytes in the body, the kidneys will filter more of these substances out into the urine, thereby lowering their concentration in the blood. Conversely, if the body is dehydrated or has a low level of certain electrolytes, the kidneys can concentrate urine and reabsorb more water and electrolytes back into the bloodstream, thus maintaining balance.

In addition to these functions, the urinary system also plays a vital role in regulating blood pH by excreting hydrogen ions and reabsorbing bicarbonate from urine, which helps maintain the body's acid-base balance. This integrated regulatory process highlights the urinary system's critical role in managing the composition of the blood and ensuring it remains within a healthy range.