Receptors

Question 1

Alpha 1

Answer 1

-Located on vascular wall of the small arteries of the peripheral, renal, and coronary circulation.
-Causes vasoconstriction
-Increase peripheral resistance
-Increase Cardiac output.
IE: Noradrenaline, Dopamine (high dose), Adrenaline (High dose).

Question 2

Alpha 2

Answer 2

-Located on the presynaptic neuron cells in the sympathetic nervous system. (CNS)
-when alpha 2 receptors are stimulated, sympathetic nervous system activity decreases.
-Inhibits the release of endogenous norepinephrine leading to vasodilation.

Question 3

Beta1

Answer 3

-Located in the myocardium and intestinal smooth muscle.
-Increase myocardial contractility, heart rate, and cardiac output.

Question 4

Beta 2

Answer 4

-Located in the bronchial and vascular smooth muscle
-Causes vasodilation of bronchioles, and peripheral and renal circulations.
-Decreases peripheral vascular resistance.

Question 5

Dopaminergic Receptors

Answer 5

Found in renal and mesenteric vessels.
-Causes vasodilation: Increases blood flow to renal and mesentery.
=At high doses, Dopamine can bind to alpha 1 and beta 2 receptors.

Question 6

V1 Receptor

Answer 6

Found in the vascular smooth muscle of the systemic, renal & coronary circulations & results in constriction.

V1 receptors found in vascular smooth muscle of the systemic, splanchnic, renal & coronary circulations

Question 7

V Receptors

Answer 7

Also known as anti diuretic hormone – regulate body’s retention of H20 (↑BP, stimulates kidneys to conserve H20 but not Na+ )
At higher doses – stimulates contraction of vascular smooth muscle, resulting in vasoconstriction of capillaries & small arterioles – increase SVR & BP

In Diabetes Insipidus there is lack of vasopressin due to destruction of part or all of the hypothalamus or pituitary gland.

Question 8

V2 Receptors

Answer 8

Found in renal collecting ducts, enhances the permeability of the collecting duct & mediates water reabsorption

V2 receptors found in distal tubules & collecting ducts of kidney

Question 9

V3 Receptors

Answer 9

– Found in pituitary & increase intracellular calcium when activated.
V3 receptors found in pituitary