lecture 6: autonomic nervous system Flashcards
sympathetic actions
fight or flight
sympathetic: short or long preganglionic
short
main NT of sympathetic
NE and Ep
main receptors of sympathetic
alpha and beta adrengeric receptors
parasympathetic actions
rest and digest
parasympathetic long or short preganglionic
long
main NT of parasympathetic
ACh
receptors of parasympathetic
muscarinic ACh
dual innervation
most organs receive input SNS and PSNS
* generally opposing effects
which division uses the adrenal medulla to send Epi through bloodstream
sympathetic
alpha1 receptor
causes Ca2+ release inside cells; common use it so stimulate smooth muscle contraction
alpha2 receptor
location is usually presynaptic; inhibits NT release
beta1 receptor
increases HR
beta2 receptor
triggers relaxation of smooth muscles along respiratory tract and ceterain blood vessels
beta3 receptor
leads to lipolysis, the breakdown of triglycerides in adipocytes
muscarine
a mushroom toxin that activiates muscarinic receptors (symptoms resemble PSNS activation)
how does SNS allow the body to carry out a fight-or-flight response
widens pupil and flattens lens for distance vision
increases cardiac output so you can run away
autonomic tone
one division is usually dominant
* ex: parasympethetic division: decrease HR; sympathetic: increase HR
* parasympathetic dominates (resting HR is ~70bpm)
