What is the significance of juxta glomerular apparatus (JGA) in kidney function?

Control by juxta glomerular apparatus :
(a)The aldosterone is a hormone secreted by the adrenal gland. It controls the level of sodium in the blood.
(b)The reabsorption is controlled by a hormone renin
produced in the kidneys. The function of the renin is the conversion of angiotensinogen into angiotensin which is produced in the liver. :
©This angiotensin stimulates the adrenal cortex to j secrete aldosterone. Aldosterone induces the distal nephron to reabsorb more water and Na+.