Autonomic nervous system 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?
-
Pre-synaptic receptors
- CNS - brainstem (inhibits outflow of the SNS)
- Medulla - decreases SNS tone
- Vagus Nerve - increases SNS tone
- Locus ceruleus - sedation and hypnosis
- Dorsal horn of spinal cord - analgesia
- PNS peripherally (inhibits NE synthesis and release–> negative feedback system)
- CNS - brainstem (inhibits outflow of the SNS)
- Post-synaptic - smooth muscle and peripheral tissue
- Platelets (non-synaptic)
Where are beta 1 receptors found?
heart, kidney, adipose tissue
Where are beta 2 receptors found?
smooth muscle and glandular tissue
physiologic response to alpha 1 receptor activation
- 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
Phyosiologic response to alpha 2 receptor activation?
- 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
physiologic response to beta 1 receptor activation?
- increased HR (chrono)
- increased conduction speed (dromo)
- increased contractility (inotropy)
- increased renin release
- iypolysis (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