Autonomic Nervous System Flashcards
muscarinic receptors
parasympathetic
metabotrophic receptor / slower
acetylcholine acts on
adrenergic receptors
sympathetic
quicker
norepinephrine acts on
nicotinic receptors
sympathetic sweat glands
quicker
acetylcholine works on
What 2 places are an exception to neurotransmitter of sympathetic system?
in sweat glands and adrenal glands acetylcholine is the neurotransmitter
neurotransmitter of sympathetic
normally norepinephrine
neurotransmitter of parasympathetic
acetylcholine
Which branch of ANS has diffuse activation?
sympathetic
many preganglionic branches
Which branch of ANS has discrete activation?
parasympathetic
few preganglionic branches
Where is origin of sympathetic?
T1-L3
Where is origin of parasympathetic?
craniosacral
where is location of sympathetic ganglia?
paravertebral sympathateic trunk
where is location of parasympathetic ganglia?
near target organs
Which adrenergic does vasodilation of thorax/brain?
beta (sympathetic)
Which adrenergic does vasoconstriction of periphery?
alpha (sympathetic)
What does sympathetic do to periphery?
vasoconstricts to shunt blood to heart/brain
What does sympathetic due to thorax/brain?
vasodilates to have more blood
3 physiological differences of hormonal release of epinephrine and nerve release of norepinephrine
1) duration of action: hormonal last longer since no reuptake
2) Hormonal release can activate receptors that do not have nerves nearby
3) No neuronal activation of Beta receptors (need a hormone release for beta receptors)
hypogastric nerve
innervates bladder
sympathetic innervation
relax detrustor (avoid peeing)
pelvic nerve
innervates bladder
parasympathetic innervation
contract detrusor (pee)
pudendal nerve
innervates bladder
somatic
nicotinic receptors contract (pee?)
Where are baroreceptors located?
aortic arch and carotid sinus
What do baroreceptors do?
detect BP
high BP can activate parasympathetic to lower BP (and vice versa for low BP)
What system is vagus nerve a part of?
parasympathetic nervous system
decreases HR
POTS
HR increases too much when you stand up
orthostatic hypotension
BP drops too much when you stand up
What is the neurotransmitter / receptor for all preganglionic synapses?
acetylcholine with nicotinic receptors
What does an agonist do?
stimulates a receptor
Most common bladder pathology in MS
overactive bladder / increased urgency
Link between CNS and bladder pathology
Brain controls micturition
lesions in CNS can cause downstream effects
Which drugs could you give to treat increased bladder urgency?
would want something to relax detrusor / bladder smooth muscle
B2-adrenergic agonist, botox, antimuscarinic
*any drug that activates the sympathetic system or deactivates the parasympathetic
How does BOTOX works?
prevents ACh release at neuromuscular junction
acetylcholine stimulates, so this leads to no contraction
How can pyridostigmine treat both POTS and orthostatic hypotension?
-stigmine = cholinesterase inhibitor
prevents breakdown of acetylcholine
acetylcholine is in both parasympathetic and sympathetic nervous system
for POTS, slow HR since acetylcholine = parasympathetic in heart
for orthostatic hypotension, increase BP by inducing vasoconstriction (sympathetic only works on vasculature)
Which branch of ANS works on vasculature?
sympathetic system ONLY
Why do autonomic drugs have many side effects?
Since many organs in the ANS have the same receptors
ex: if something works in on a alpha-adregeneric receptor, these are in multiple sites in body
