ANS Flashcards
Main activities of the ANS
regulation of smooth muscles
regulation of the heart
regulation of secretory glands
primary ANS neruotransmitters
Acetylcholine, norepinephrine, epinephrine
all drugs work either by increasing or decreasing receptor activation
acetylcholine
used at most junction of peripheral nervous system
undergoes reuptake to be stroed for reuse
Acetylcholinesterase
enzyme that breaks down Ach
psuedocholinesterase
destroys Ach
norepinephrine
released by most postgaglionic neurons
most adrenergic agonist drugs inhibit NE reuptake or inactivation or promote release
MAO
enzyme that destroys NE
COMT
enzyme that destroys NE usually in the blood stream
Epinephrine
made in adrenal medulla
released into blood stream and traveks to target organs
termination by hepatic metabolism
works on all 4 receptors
SNS nerve fibers
short preganglionic and long postganglionic nerve fibers
one preganglionic fiber activates many postganglionic fibers
Fight/flight response
SNS CV regulation
maintaing blood flow to the brain, redistributing blood, compensating for the loss of blood
SNS body temp regualtion
regulates blood flow to the skin
promotes secretion of sweat
induce piloerection (hair standing on edge)
SNS CV effects
increases heart rate
increases BP
increases contraction
SNS bronchiole effecs
bronchodilation
SNS skin effect
increases sweating
SNS eye
pupil dilation
SNS pancreas
decreased insulin
increased blood sugar
SNS GI
decreased peristalsis
SNS GU
relaxes smooth muscle, constricts sphincter, inhibits voiding
SNS peripheral blood vessels
vasoconstriction
SNS respiratory
increases rate and depth of respiration
alpha 1 receptors/ responses
in smooth muscle, (eye, blood vessles, sex organs, bladder) on postsynaptic membrane
respond to all 3 NT
constriction of blood vessels, dilation of pupil, ejaculation, contraction of bladder neck and prostate
activation increases vascular smooth muscle
alpha 2 receptor
on presynaptic membrane
inihibitory- specifically of norepinephrine
minimal clinical significance
Beta 1 receptorsd
in heart- increased rate, force of contration, AV conduction
In kindey- Renin release which causes vasoconstriction