Describe the structure and functioning of nephrons.

Nephrons are the basic filtering units of kidneys. Each kidney possesses large number of nephrons, approximately 1-1.5 million. The main components of the nephron are glomerulus, Bowman’s capsule, and a long renal tubule.

Structure of a nephron

Functioning of a nephron:

• The blood enters the kidney through the renal artery, which branches into many capillaries associated with glomerulus.

• The water and solute are transferred to the nephron at Bowman’s capsule.

• In the proximal tubule, some substances such as amino acids, glucose, and salts are selectively reabsorbed and unwanted molecules are added in the urine.

• The filtrate then moves down into the loop of Henle, where more water is absorbed.

• From here, the filtrate moves upwards into the distal tubule and finally to the collecting duct. Collecting duct collects urine from many nephrons.

• The urine formed in each kidney enters a long tube called ureter. From ureter, it gets transported to the urinary bladder and then into the urethra.