Question

What are the processes involve in the formation of urine?

Answer 1

FORMATION OF URINE:

The process of urine formation includes the following basic processes-glomerular filtration, tubular reabsorption, tubular secretion and excretion.

Glomerular Filtration:

1. It occurs in the glomerulus, which receives impure blood through different arterioles of the renal artery.
2. The blood entering the glomerulus mainly contains water with dissolved salts, urea, uric acid and glucose.
3. The narrowing of blood capillaries causes an increase in the pressure of the blood, due to which the water and insoluble molecules present in the blood get filtered out into the cavities of Bowman's capsule.

Tubular reabsorption:

1. The filtrate of the glomerulus passes through the thin walls of Bowman's capsule.
2. It moves forward in the renal tubule.
3. The reabsorption of useful substances, such as glucose, amino acids, water and some inorganic salts takes place by the renal blood capillaries.

Tubular secretion:

The remaining liquid along with some additional wastes such as urea and uric acid is passed through both the ureters and collected in the urinary bladder.

Excretion:

1. The urine from the kidneys reaches into the urinary bladder via ureters.
2. When the urinary bladder is full, urine is passed out from the body through the urethra.