Explain the auto regulatory mechanism of GFR.

Explanation

Auto Regulation of GFR : The kidneys have built in mechanisms for the regulation of glomerular filteration rate. One such efficient mechanism is carried out by juxta glomerular apparatus. Juxta glomerular apparatus is a special region formed by cellular modifications in the distal convoluted tubule and the afferent arteriole at the location of their contact. A fall in GFR can activate the juxta glomerular cells to release an enzyme called renin, which catalyses the conversion of angiotensinogen into angiotensin-I and further converted to angiotensin-II by action of an enzyme angiotensin converting enzyme. Angiotensin-II stimulate the adrenal cortex to secrete aldosterone. Alsdosterone causes reabsorption of `Na^(+)` and water from DCT and collecting duct to reduce loss through urine and also promotes the secretion of `K^(+)` ions into the DCT and CD (collecting duct). It leads an increase in the blood pressure and GFR.