6- Autonomic Physiology Review Flashcards
CNS =
brain and spinal cord
somatic nervous system and the autonomic nervous system =
peripheral nervous system
sympathetic preganglionic fibers are _______ compared to postganglionic.
parasympathetic preganglionic fibers are _____ compred to the postganglionic.
symp pre = short
symp post = long
para pre = long
para post = shortN
what system in the ANS does not have post ganglionic fibers?
adrenal medulla
releases Epi, NE, Dopa, and peptides directly into blood stream without post ganglionic fibers
symp cell bodies of preganglion neurons are located…
in column of spinal cord T1-L4 “thoracolumbar”
“cranio-sacral”
parasympathetic nervous system
GI tract motility
myeteric or Auerbach plexus of ENS
ion and fluid transport in GI
submucosal or Meissner’s plexus
can the ENS function without input from symp and para?
yes
most organs receive both symp and para innervation. What are the sympathetic only exceptions?
blood vessels hair follicles sweat glands liver adrenal glands kidneys
in most organs symp and para have opposing effects. What is the exception?
salivary glands - produce similar rather than opposing effects
all somatic n. release …
Ach
all preganglionic fibers in the ANS release …
Ach
para post-ganglionic fibers release…
Ach
symp post-ganglionic fibers are …
adrenergic or dopaminergic
which symp is not adrenergic or dopaminergic?
thermoregulatory sweat glands
- possess muscarinc receptors and respond to Ach (like para) BUT are regulated by symp post ganglionic fibers
what type of receptors are there for symp innervation to renal vascular smooth muscle
D1 for dopamine
cardiac and smooth muscle, gland cells, and nerve terminals receive para and symp innervation. What are the respective receptors and transmitters?
para- Ach - M
symp - NE - alpha, beta
what are cotransmitters?
neurons release more than one transmitter, each of which interact with specific receptors and produce effects both pre and post synaptically
one NT affects teh release of another via actions on receptors on a presynaptic nerve ending that respond to a dif. NT tan the one secreted by that n. ending
heterotropic interaction
ex: release of NE inhibits Ach release and causes a different response than Ach would
NT by binding to presynaptic receptors, affects the nerve terminals from which it is being released
homotropic interaction
long term blockade of post-synaptic receptors is associated with ___________ when the blocking agent is removed
rebound hypersensitivity
ex: rebound hypertension when beta adrenergic receptor antagonist are abruptly withdrawn
3 mechanisms of withdrawl rebound hyperactivity/ disuse hyperactivity
- proliferation of receptors
- loss of mechanism of NT removal
- increased postjunctional responsiveness
