Describe briefly the regulation of kidney function by following :
Renin

Explanation

Renin : The smooth muscle cells of both the afferent and efferent arterioles are swollen and contain dark granules. These cells are called juxtaglomerular cells . A fall in glomerular blood flow or glomerular blood pressure or high blood potassium activate the JG cells to release renin. Renin converts angiotensinogen in blood into angiotensin II. The later cause blood vessels to constrict and increase blood pressure. Angiotensin also stimulates the secretion of aldosterone by the adrenal cortex, thus infusing the reabsorption of sodium ions by the DCT and that of water through collecting ducts