descending colon > transverse colon"Actions of Angiotensin IIBlood Vessels(AT1A receptors)Brain(AT1a receptors)Adrenal Cortex(AT1B receptors)Others* Potent arteriolar (Vaso) constrictor causing:-Rise in systolic and diastolic BP-Rise in total peripheral resistance* Its pressor activity is decreased in cirrhosis and in Na* depleted individuals. Because circulating angiotensin II is increased in those conditions, which down regulates angiotensin receptors in vascular smooth muscle* It does not penetrate blood brain barrier, but triggers responses by acting on circum ventricular organs (out side BBB)* Area postrema is primarily responsible for pressure potentiation. Angiotensin II acts here to decrease the sensitivity of baroreflex* Dipsogenic effect (i.e. Increase thirst or water intake) is due to action of subfornical organ and organum vasculosum of lamina terminalis.* | Antidiuretic hormone(ADH) or vasopressin) from posterior pituitary* | ACTH* Increase secretion of aldosterone which:- Promotes Na and water reabsorption0- Expands ECF (leading to CO)- Facilitates K+ excretion* Direct effect on PCT to increase Na+ reabsorption by increasing Na+ - H+ exchange* Contraction of mesangial cells with resultant decrease in GFR* Direct action on post ganglionic sympathetic neurons facilitates release of norepinephrine">