What is the function of the kidney?

The main function of the kidney is to filter waste products and excess substances, such as water, salts, and minerals, from the blood to form urine. The kidneys also help regulate blood pressure, produce hormones that control red blood cell production and calcium metabolism, and maintain the body's acid-base balance.

Functions of the Kidney:

1. Excretion of Waste Products:
- Filters blood and removes waste products (e.g., urea, creatinine, uric acid)
- Concentrates these waste products into urine for elimination

2. Regulation of Fluid and Electrolyte Balance:
- Conserves water and electrolytes (e.g., sodium, potassium, chloride)
- Regulates the volume and composition of body fluids

3. Acid-Base Balance:
- Removes excess acids or bases from the blood
- Maintains the pH balance of body fluids

4. Hormone Production:
- Secretes erythropoietin, which stimulates red blood cell production
- Produces renin, which regulates blood pressure
- Produces vitamin D, which is essential for calcium absorption

5. Metabolism:
- Gluconeogenesis: Produces glucose from non-carbohydrate sources during starvation
- Detoxification: Filters toxins and drugs from the blood

6. Excretion of Drugs and Toxins:
- Filters and excretes medications, toxins, and other foreign substances from the blood

7. Regulation of Blood Pressure:
- Contributes to the renin-angiotensin-aldosterone system, which controls blood vessel tone and blood pressure

8. Erythrocyte Destruction:
- Removes old or damaged red blood cells from the bloodstream