sympathetic system: adrenergic receptors in human body

receptor for sympathetic system we called adrenergic receptors which are divided into 2 families: a receptors and b receptors.

a receptors:

1. a1 receptors:

• vasoconstriction : increase peripheral resistance and blood pressure
• glycogenolysis, gluconeogenesis in liver
• increase tone of sphincters in git and bladder
• decrease tone oof motility of git
• contraction of pregnanat uterus
• mydriasis by contraction of dilator pupilla muscle.

    2. a2 receptors:

• presynaptical localization: result in decrease release of noradrenaline
• postsynaptical localization: decrease insulin release by b cell, decrease motility , tone and secretion in git
• aggregation of platelets
• vasoconstriction
• inhibit acetylcholine release

b receptors:

1. b1 receptors:

• positive effect on heart: increase heart rate, contractility, dromotropic effect(conductivity), bathmotropic(excitibility)
• kidney-juxtaglomerular : increase renin secretion

2. b2 receptors :

• vasodilation of blood vessels in skeletal muscles and coronary arteries.
• bronchodilation
• relaxation of visceral smooth muscle
• increase muscle and liver glycogenolysis
• increase insulin release by b cells
• increase glucagon release
• increase salivation-thick
• decrease tone of bladder detrussor muscle
• decrease tone of uterine smooth muscle
• skeletal muscle tremor

3. b3 receptors

• lipolysis