ANS Review Flashcards
anatomical subdivisions of the ANS
cranial parasympathetic nerves
thoracic and lumbar sympathetic nerves
sacral parasympthatic nerves
preganglionic nerve fibers of the ANS
cell bodies originate entirely within the CNS, myelinated terminals
synapse in the autonomic ganglai which are entirely outside the CNS
postganglionic nerve fibers of the ANS
cell bodies entirely within the autonimic ganglia
non-myelinated
neuroeffector junctions
formed by post-ganglionic nerve terminals synapsing with effectors
sympathetic ganglia
near the spinal cord at considerable distance from ultimate effectors
one sympathetic preganglionic fiber distributres its activity in a diffuse fashion to many postganglionic fibers at distant sites
parasympathetic ganglia
located very near or even embedded int he target effector with a preganglionic fiber synapsing nearby the effector with its postganglionic partner
types of ANS nerves and their neurotransmitters
parasympathetic - ACh and ACh
sympathetic ACh and Nor
sympathetic cholinergic ACh and ACh
adrenal medulla
ACh and release of Adr and Nor into blood
control of popul diameter
sympathetic stimulation - myadrasis from superior cervical ganglion, norepinephrine
parasympathetic stimulation miosis miosis - oculomotor nerve, acetylcholine
sympathetic vs. sympathetic effects on bronchioles
sympathetic dilation
parasympathetic constriction
sympathetic vs. sympathetic effects on the gastro-intestinal
sympathetic constipation
parasympathetic defecation
sympathetic vs. sympathetic effects on the urinary bladder
sympathetic urinary retention
parasympathetic micturition
sympathetic vs. sympathetic effects on the heart
sympathetic increases heart rate and contractile force
parasympathetic decreases heart rate and has no direct effect on contractile force
sympathetic vs. sympathetic effects on the liver
parasympathetic - glycogen synthesis
sympathetic glycogenolysis and gluconeogeneiss
sympathetic vs. sympathetic effects on the liver on fat depots
sympathetic fatty acid release
parasympathetic no effects
sympathetic vs. sympathetic effects on the liver
sympathetic causes constriction via alpha1 adrenoreceptors - major determinant of blood pressure
parasympathetic has no effect
parasympathetic effect on sexual function
promotes erection and mucous secretion, transmitter here is nitric oxide
sympathetic effect on sexual function
smooth muscle contractions and secretions in both males and females
somatic response of sexual function
after parasympathetic and sympathetic actions there is a somatic response that leads to skeletal muscle contractions and ejaculation in males
detumescence
loss of arousal via sympathetic alpha1 vasoconstriction
piloerector contraction
hairs stand on end via sympathetics
sympathetic vs. sympathetic effects on the spleen
sympatetic contraction and release of erythrocytes, no parasympathetic effects
sympathetic vs. sympathetic effects on salivary secretion
parallel actions
sympathetic small volume of potassium and water
parasympathetic serous and watery
focal hyperhydrosis
excessive sweating in the armpits, treatable with BOTOX A
sympathetic vs. sympathetic effects on sweating
apocrine glands are not innervated
responds to epinephrine released from the adrenal medulla
parasympathetic secretions
nasopharyngeal glands
acid secreting glands
lachrimal glands
exocrine pancreas
endocrine pancreas
sympathetic vs. sympathetic effects on insulin secretion
sympathetic inhibits secretion
parasympathetic stimulates secretion
Which division of the ANS dominates normally?
parasympathetic tone predominates
exception is the sympathetic tone to blood vessels, which is unopposed by parasympathetic innervation
pupil effects of Lambert-Eaton, Myasthenia Gravis, and Botulism
LEMS - pupils constricted a little but responds sluggishly to light, wrong flavor of calcium channel blocked
MG - does not affect pupils because it is a strictly motor neuron/muscle defect
botulism - fixed dilated pupils because BOTOX blocks ACh release of mydriasis
sympathetic tone and blood vessels, state the relevant equations
main control of blood pressure
BP = CO x TPR
TPR = (length x viscosity x constant)/(pi x radius^4)
small changes in radius has large impacts on the total peripheral resistance
barostatic reflex
increased blood pressure sensed by stretchr eceptors in teh aortic arch and carotid sinus
increases firing of nerves IX and X, synpase on the nucleus tractus solitarius (NTS), which stimulates the vagal nucleus
stimulation o the vagus produces a slowing of the heart, reflex bradycardia
inhibits vasomotor center and relfexively reduces smpyathetic tone to the periphery
orthostatic hypotension
failure to maintain arterial pressure to do low vasomotor tone
produced by drugs that block the sympathetic link to the periphery
drugs that block the sympathetic link to the periphery
alpha1 blockers
adrenergic neuron blockers
ganglion blockers
micturition
parasympathetic spinal reflex
critical threshold is reached
sensory nerves send impulses to the spinal cord
activity emerges from the sacral spinal cord
enteric division of the ANS
consists of submucous and myenteric plexi of neurons
third division of the ANS
controls the peristaltic reflex, which can occur very effectively in the absence of any extrinsic neruonal connections to the gut wall
an enormous number of different neurotransmitters
vagus nerve orders the events to occur but the enteric division carries out the peristaltic reflex
