Question

Effects of sympathetic (adrenergic) receptor stimulation & blocking
Receptor	Location	Adrenergic	Adrenergic blocker
Alpha 1	Eye
	Arterioles of skin, organs & mucous membranes
	Veins
	Male Sex Organs
	Prostate Capsule
Alpha 2	Presynaptic nerve terminals
Beta 1	Heart
	Kidney
Beta 2	Arterioles of heart, lungs, and skeletal muscle
	Bronchi
	Uterus
	Liver
	Skeletal muscle

Answer 1

Adrenergic receptors are receptors of sympathetic system. They can bind with norepinephrine and epinephrine. They are classified into alpha and beta receptors. They again classified into alpha 1, alpha 2, beta 1, beta 2 and beta 3 by the specificity of their drug that stimulate or block them and their specific responses. Activation of alpha 1 and beta 1 cause excitation and activation of alpha 2 and beta 2 cause inhibition of effector tissue. Beta 3 receptors are only seen in adipose tissue which helps in thermo regulation.

Effects of sympathetic (adrenergic) receptor stimulation & blocking
Receptor	Location	Adrenergic	Adrenergic blocker
Alpha 1	Eye	dilation of pupil	constriction of pupil . reduce secretion of aqueous humor
	Arterioles of skin, organs & mucous membranes	increase sweating, eruction of hair follicles closing of sphincters secretion of potassium and water	vasodilation relax spinctures
	Veins	vasoconstriction	decreased peripheral vascular resistance due to vasodilation
	Male Sex Organs	contraction of smooth muscles of vas deferens, seminal vesicle	relax smooth muscles of vas defens, seminal vesicle
	Prostate Capsule	ejaculation of semen	relax smooth muscles of prostate
Alpha 2	Presynaptic nerve terminals	inhibit neurotransmitter release	helps release of neurotransmitter
Beta 1	Heart	increase force and rate of contraction	decreased heart rate, reduce blood pressure
	Kidney	secretion of Anti diuretic hormone and Renin	reduce the activity of renin -angiotensin -aldosteron mechanism
Beta 2	Arterioles of heart, lungs, and skeletal muscle	vasodilation, dilation of airways, relaxation of organ walls	vasoconstiction, increase airway resistance, reduction of exercise capacity in skeletal muscle.
	Bronchi	bronchodilation	bronchoconstriction
	Uterus	inhibit contraction of nonpregnant uterus	promote contraction of uterine walls
	Liver	glycogenolysis ( breakdown of glycogen into glucose)	inhibit glycolysis, gluconeogenisis and lypolysis
	Skeletal muscle	relaxation of muscle	contraction of musles