Question

Why do we say that kidney is a homeostat organ? Briefly explain.

Answer 1

1. A homeostat organ maintains a constant internal environment in the body. The kidneys perform this function by regulating the composition of blood and tissue fluids.
2. They regulate the amount of water in the body by adjusting the reabsorption of water in the renal tubules and collecting ducts.
3. They maintain the concentration of mineral salts and ions in the blood through selective reabsorption and tubular secretion.
4. The kidneys help maintain the osmotic pressure of blood, a process known as osmoregulation.
5. They help maintain the acid-base balance and normal pH of the blood by removing excess hydrogen ions.
6. They remove nitrogenous wastes such as urea, uric acid and ammonia, along with other toxic substances.
7. Kidney function is also regulated by the antidiuretic hormone (ADH). When there is excessive loss of water, ADH increases water reabsorption and reduces urine formation.
8. Thus, by controlling water, salts, wastes and blood pH, the kidneys maintain homeostasis and are called homeostat organs.