autonomic nervous system II Flashcards
once a somatic neuron release ACh, what type of nicotenic receptor does it bind to?
N1
once a parasymp or sym neuron releases ACh, what type of receptor does it bind to?
N2
what is the N2 receptor antagonist?
hexamethonium
what is the N1 receptor antagonist?
d-tubocurarine
in parasympathetic neurons what is the receptor type?
muscarinic cholinergic
what is atropine?
a general muscaronic cholinergic receptor antagonist
muscarinic cholinergic receptors M1, M3 & M5 linked to?
activation of PLC, increased intracellular calcium and DAG
muscarinic cholinergic receptors M2 & M4 linked to?
inhibition of adenylyl cyclase and decreased cAMP generation
in regards to parasymp control, what does cranial nerve 3 do?
pupillary constriction
in regards to parasymp control, what does cranial nerve 7 do?
lacrmal gland and nasal mucosal secretions
also salivary glands
in regards to parasymp control, what does cranial nerve 9 do?
salivary glands
in regards to parasymp control, what does cranial nerve 10 do?
GI paralysis/increased motility and sphincter relaxation, bronchial constriction, decreased HR
in regards to parasymp control, what does the pelvic splechnics do?
relax ureter and sphincter in conjunction with contraction of the detrusor muscle during urination, rectal emptying and penile erection
where does the vagus originate?
dorsal motor nucleus and in some of the nuclus ambiguus (where there is also IX)
what are the 4 parasymp pre gang fibers originating in the brain stem?
nerve III (ocuolomotor) nerve VII (facial) nerve IX (glossopharyngeal) nerve X (vagus)
what is the nucleus tractus solitarius (NTS)?
it receives visceral afferents and is part of the larger visceral control system
what does the myenteric (Auerbach) mucosa plexus control?
gut motility
what does the submucosa plexus control?
secretions
describe the parasympathetic control on the enteric nervous system
enhances motility and secretions
describe the sympathetic control on the myenteric plexus in the gut
Norepinephrine is released from the sympathetic nerve terminals in the myenteric plexus, hyperpolarizing and relaxing the smooth muscle in the gut and causing sphincted constriction
describe the parasymp control on micturition
constriction of the detrusor muscle and relaxation of the internal sphincter
what 2 types of receptors are in the internal sphincter?
alpha 1 adrenoreceptor for sympathetic
M muscarinic cholinorepector for parasympathetic
what 2 types of receptors are in the detrusor muscle?
beta 2 adrenoreceptor for symps
M muscarinic cholinorepector for parasympathetic
what five areas of the brain house control centers for autonomic nervous system?
hypothalamus brainstem midbrain pons medulla
what would be the result from a transection of the brain stem just below the medulla?
decrease in arterial blood pressure to less than 1/2 the normal value
list some examples when visceral afferents overwhelm cortical function (“nothing else seems to matter”)
hunger, nausea, dyspnea, visceral pain, bladder & bowel distention, hypothermia, hyperthermia
how can seizures be induced?
from massive sympathetic output and arrhythmias
where do the symptoms of fear and panic attacks come from?
initiation of the flight or flight (sympathetic)
why does nervousness before a test cause diarrhea?
because there is an imbalance between the PNS and the SNS causing insufficient transit time to reabsorb water
Which adrenergic receptor is predominantly found in the heart?
B1
In skeletal muscle, there are two types of adrenergic receptors, which causes vasodilation and which causes vasoconstriction?
alpha 1 - vasoconstriction
beta2 - vasodilation
Which adrenergic receptor is found in the bronchioles?
B2
Which receptor is responsible for erection? ejaculation?
erection - M
ejaculation - alpha1
which adrenergic receptors are found in the skin?
alpha
Which receptor is responsible for gland secretion?
M
Which receptor is responsible for ciliary dilation? Iris dilation?
ciliary - beta
iris - alpha 1
Sympathetic causes pupil DILATION
