The different parts of the nephron are marked in the picture below-

(a)

(b) Functions of a structural and functional unit of the kidney:

The structural and functional unit of the kidney is Nephrons. The important functions of nephrons are:

1. Formation of urine: The most important function of the nephron is the formation of Urine. The urine is formed by the three different steps- filtration, tubular reabsorption, and tubular secretion.

2. Reabsorption- It also reabsorbs the useful substances from the urine. The substances reabsorbed by the nephrons are glucose, amino acid, salts, and water.

3. Regulation of water concentration- It regulates the concentration of water and soluble substances. The secretion of H⁺ ions helps to regulate the pH of the blood.

(c) One function of an artificial kidney:

The artificial kidney is useful in kidney failure. It is used to clean the patient’s blood.

Explanation: The kidneys are used in the filtration of the blood. If due to any circumstances the kidney fails, it will affect the quality of the blood and hence urine formation will be affected and the body will lose useful substances. Hence, the artificial kidney helps to clean the patient’s blood.