lecture 24-ANS Flashcards
where are the cell bodies of preganglionic neurons located
within CNS
what is the neurotransmitter for preganglionic neurons in ANS
Ach
where are cell bodies for postganglionic neurons located
in peripheral ganglia
what is the neurotransmitter for postganglionic neurons
Ach in para; norepinephrine in sym.
what part of the spinal cord are sympathetic preganglionic neurons associated with
T1-L2
what type of fibers are postganglionic sympathetic fibers
type C
what do postganglionic sympathetic fibers control
blood vessels, sweat glands, piloerector muscles
where does the thoracic sympathetic chain lie
against neck of ribs and costovertebral junctions
what are the 12 thoracic ganglia pairs referred to as collectively
stellate ganglion
how do preganglionic sympathetics exist the thoracic sympathetic chain
as direct fibers
what are the functions of the cardiopulmonary splanchnic nerves
coronary artery dilation, increase heart rate, bronchodilation
where do splanchnic nerves synapse
prevertebral ganglia
where do greater splanchnic nerves synapse and what part of the spinal cord are they
T5-T9 and synapse in celiac ganglion
where do lesser splanchnic nerves synapse and what part of the spinal cord are they
T10-T11 and synapse in superior mesenteric ganglion
where do least splanchnic nerves synapse and what part of the spinal cord are they
T12 and synapses in aorticorenal ganglion
what system is the adrenal medulla stimulated by
sympathetic system
what does the adrenal medulla secrete
epinephrine and norepinephrine
when does alarm or stress response occur
when there is a mass discharge of the entire sympathetic system (fright, fear, severe pain)
where are the majority of parasympathetic fibers located
in vagus nerve (CN 10)
what do postganglionic parasympathetic fibers use as a neurotransmitter
Ach
what cranial nerves carry parasympathetic signals
oculomotor, facial, glossopharyngeal, vagus
what is the function of the oculomotor nerve
supplies 4 of 6 extrinsic muscles of the eye and the legator palpebrae superioris
what is the preganglionic function of CN III
from edinger-westphal nucleus to ciliary ganglion
what is the postganglionic function of CN III
from ciliary ganglion to sphincter pupillae muscle
what is the function of the facial nerve
primary motor nerve to muscles of facial expression. carries sensation of taste from anterior 2/3 of tongue
what is the preganglionic function of CN 7
from superior salivatory and lacrimal nuclei to submandibular/sublingual ganglia
what is the postganglionic function of CN 7
to lacrimal gland, submandibular gland, sublingual gland, and mucous glands of mouth and nose
what is the function of the glossopharyngeal nerve
carries general sensation and sensation of taste from posterior 1/3 of tongue
what is the postganglionic function of CN 9
to parotid gland
what is the preganglionic function of CN 9
from inferior salivatory nucleus to otic ganglion
what is the function of the vagus nerve
motor supply to muscles of 4th and 5th pharyngeal arches and is important in swallowing and speaking
what is the preganglionic function of CN 10
from dorsal motor nucleus
what is the postganglionic function of CN 10
myenteric plexus of wall of gut tube all the way to the left colic flexure
what does the vagus nerve run parallel to
esophagus
describe the left recurrent laryngeal nerve from the left vagus route
hooks around arc of aorta to left ligamentum arteriosum
describe the right recurrent laryngeal nerve from right vagus route
arises in neck, not thorax
what enzyme is needed to convert acetyl-CoA + choline to acetylcholine
choline acetyl-transferase
what enzyme is needed to convert acetylcholine to choline and acetate ion
acetylcholinesterase
what amino acid is the precursor of norepinephrine
tyrosine
how is norepinephrine converted to epinephrine
methylation
what can destroy nerepinephrine
monamine oxidase and COMT
where is monamine oxidase found
in nerve endings
where are muscarinic receptors found
on all effector cells stimulated by postganglionic cholinergic neurons
where are nicotinic receptors found
in autonomic ganglia at synapses between preganglionic and postganglionic neurons
what alpha receptor is involved in the inhibition of neurotransmitter release
alpha2
what does beta1 do
cardioacceleration, increased myocardial strength, lipolysis
what does beta2 do
vasodilation, intestinal and uterus relaxation, bronchodilation, calorigenesis, glycogenolysis, bladder wall relaxiation
what is beta3 involved in
thermogenesis
what does reserpine do
blocks synthesis and storage of norepinephrine
what does guanethidine
blocks release of norepinephrine
what does phenoxybenzamine/phentolamine do
blocks sympathetic alpha receptors
what does propranolol do
blocks sympathetic beta1 and beta2 receptors
what does metoprolol do
blocks most sympathetic beta1 receptors
what does hexamethonium do
blocks transmission through autonomic ganglia
what does inhibit acetylcholinesterase
neostigmine, pyridostigmine, ambenonium
what drugs block cholinergic activity
atropine, homatropine, scopolamine
what is the effect of sympathetics and parasym on the eye
sym: pupil dilation. para: pupil constriction and lens focusing
what are the glands of the lower GI tract mostly stimulated by
enteric system
how does the sympathetic system effect arterial pressure
results in acute increase in arterial pressure but little effect long term
how does the parasympathetic system effect arterial pressure
decreases pumping of heart but little effect on blood pressure
how does sympathetic and parasympathetic generally effect endodermal structures
sym inhibits and parasym excites
