Question

Describe the mechanism of urine formation.

Answer 1

Mechanism of urine formation:

1. Urine formation occurs in 4 steps Ultrafiltration, reabsorption, tubular secretion, and concentration of urine.

Ultrafiltration:

1. Blood enters through the glomerulus under pressure, and most of the small solutes and water get filtered.

Reabsorption:

1. The glomerular filtrate enters the PCT, and 75% of electrolytes get reabsorbed.

Tubular secretion:

1. Tubular secretion occurs mostly in the distal convoluted tubules and some in proximal convoluted tubules.
2. It is responsible for the excretion of waste from the body.

Concentration of urine:

1. This occurs in the collecting ducts and DCT.
2. It reabsorbs the excess water.