The purpose of making urine is to filter out waste products from the blood.
Explanation:
The basic filtration unit in the kidneys is a cluster of very thin-walled blood capillaries called glomerulus. Each capillary cluster in the kidney is surrounded by the cup-shaped structure called Bowman’s capsule that collects the filtered urine. Each kidney has large numbers of these filtration units called nephrons.
Some substances in the initial filtrate, such as glucose, amino acids, salts, and a major amount of water, are selectively reabsorbed as the urine flows along the tube. The amount of water reabsorbed depends on how much excess water is in the body and how much dissolved waste there is to be removed.
The urine formed in each kidney eventually enters a long tube, called the ureter, which connects the kidneys with the urinary bladder. Urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge to pass it out through the urethra. We can usually control the urge to urinate.
