NEPHRON

The nephrons are structural and functional units of the kidneys. These are tiny tubules in the kidney, which filter the blood  (» 1 x 106/kidney).

BOWMANS CAPSULE

Force filtration in Bowman's capsule causes much of the water and ions and smaller molecules to leave the blood and enter the proximal convoluted tubule.

THE PROXIMAL TUBULE

the peritubular capillaries contain blood in a hyperosmotic state, so much of the water filtrate reenters (reabsorption) the blood by osmosis.  Active transport also returns sodium (chloride following passively), glucose, and amino acids to the blood.

COLLECTING DUCTS

Water leaves the collecting ducts in response to antidiuretic hormone (ADH), which is secreted by the posterior pituitary in response to osmotic conditions in the blood (actually detected by the hypothalamus).

URINE

Urine is the excretory product produced by the kidneys. It is pale yellow solution, comprising of urea, water, salts, other trace solutions (toxins…)

PROCESS OF URINE FORMATION

Nephron structure