Receptor Review (alpha, beta) Flashcards
Where are alpha 1 receptors found?
peripherally in a variety of tissues (vascular smooth muscle, glands) innervated by sympathetic postganglionic neurons
Where are alpha 2 receptors found?
1) presynaptic nerve terminals of sympathetic postganglionic neurons (inhibits NE synthesis and release–> negative feedback system)
2) postsynaptic alpha 2 receptors in brainstem (inhibits outflow of the SNS)
3) peripheral tissues
4) stimulation of alpha 2 in the substantia gelatinosa (promotes analgesia)
Where are beta 1 receptors found?
heart, kidney, adipose tissue
Where are beta 2 receptors found?
smooth muscle and glandular tissue
What response is seen when alpha 1 receptors are activated?
- pupils dilate (mydriasis “OH MYdriasis”)
- vasoconstriction of arteries (increased SVR)
- vasoconstriction of veins (increased preload)
- release of RBCs from the spleen
- decrease renin release
- relax stomach and intestines
- decrease insulin secretion and increase glucagon secretion
- contract the uterus
What response is seen when alpha 2 receptors are activated?
- decrease insulin secretion
- inhibit NE synthesis and release (negative feedback) in presynaptic nerve terminals of sympathetic postganglionic neurons
- in brainstem, inhibit outflow of SNS
- in substantia gelatinosa, promote analgesia
What response is seen when beta 1 receptors are activated?
- increased HR (chrono)
- increased conduction speed (dromo)
- increased contractility (inotropy)
- increased renin release
- lipolysis (breakdown of fats)
What response is seen when beta 2 receptors are activated?
- vasodilation in skeletal muscle vessels (decreased SVR)
- bronchodilation
- increased secretions
- glycogenolysis and gluconeogenesis (increased glucose)
- relax gallbladder
- relax urinary bladder wall
- increase insulin secretion
- relax uterus
- stimulate Na-K pump (decrease plasma K+; 3 Na Out, 1 K+ in)
______ stimulation promotes hyperglycemia (secondary to glycogenolysis and gluconeogenesis).
beta 2
______ stimulation promotes hypokalemia.
beta 2 (stimulation of Na-K pump)
Side effects of _____ receptor stimulator, _________, include hyperglycemia, hypokalemia, and tachycardia (d\t some beta 1 receptor activity)
beta 2 receptor; ritodrine (yutopar)
Relaxes the uterus?
beta 2
Increased chronotropy, dromotropy, and inotropy?
beta 1
Vasoconstriction of arterial systemic vessels and veins?
alpha 1
Bronchodilation and increased secretions?
beta 2
