3- autonomic Flashcards
what are 3 choline esters
acetylcholine
carbachol
bethanechol
how are choline esters absorbed in the GI tract
poorly
what is the main effect of muscarinic agonists
parasympathomimetic (stimulates the parasympathetic system)
what is the main effect of nicotinic agonists
parasympathetic and sympathetic effects in autonomic ganglia and skeletal muscle
is ACh nicotinic or muscarinic
both
is carbachol nicotinic or muscarinic
both
is bethanecol nicotinic or muscarinic
muscarinic
what makes carbachol and bethanecol different from ACh
they are not hydrolyzed by acetylcholinesterase
what are 3 muscarinic agonists
muscarine
oxotremorine
pilocarpine
what is acetylcholine
a choline ester
what is carbachol
a choline ester
what is bethanechol
a choline ester
what is muscarine
muscarinic agonist
what is oxotremorine
muscarinic agonist
what is pilocarpine
muscarinic agonist
what are the main effects of muscarinic agonist
parasympathomimetic
what do muscarinic agonists do to the cardiovascular system
slow HR, decrease force&rate of contraction
what do muscarinic agonists do to endothelium
the muscarinic receptors in the endothelium that cause release of NO that causes relaxation
when does ACh not cause relaxation in the endothelium
when the endothelium is not intact
what do muscarinic agonists do to the respiratory system
contraction of bronchiole smooth muscle, increased secretion of mucous
why can muscarinic agonists be bad for asthmatics
lots of mucous and bronchiole contraction makes respiration less efficient
what do muscarinic agonists do to the GI tract
increases saliva and stomach acid secretion, motility and peristalsis
what does muscarinic agonists do to the bladder
stimulates detrusor muscle, relaxes trigone and internal sphincter (promotes voiding)
what are the CNS effects of nicotine
mild stimulation, can cause emesis, coma at high doses
does nAChR stimulate the sympathetic or the parasympathetic branch
both of them
what does nicotine do to the cardiovascular system
hypertension
is nicotines cardio effect parasympathetic or sympathetic
sympathetic
is nicotines GI effect parasympathetic or sympathetic
parasympathetic
what does nicotine do to the GI system
increase secretion and motility
what are the skeletal muscle effects of nicotine
depolarization and excitation
-it can cause a small twitch or even a strong contraction of a whole muscle
what do anticholinesterases do to nicotinic and muscarinic receptors
indirectly stimulate by preventing hydrolysis of ACh
what is edrophonium
a simple alcohol anticholinesterase
what is neostigmine
carbamic esters of alcohols with quaternary or tertiary ammonium group
-an anticholinesterases
what is malathion
insecticide anticholinesterase
organophosphate
what is soman
nerve gas
anticholinesterase
organophosphate
are anticholinesterases well absorbed in the body
yes, via skin gut lung and conjuctiva
what effects are anticholinesterases similar to
direct acting cholinergic agonists
what would anticholinesterases do to respiration
constrict bronchiole, increase secretion (they are like cholinergic agonists which are like parasympathetic agonists)
what would anticholinesterases do to gut
increase motility
they are like cholinergic agonists which are like parasympathetic agonists
what would anticholinesterases do to heart
slow heart rate, decreased cardiac output
they are like cholinergic agonists which are like parasympathetic agonists
what do anticholinesterases do to neuromuscular transmission
increase strength of contraction -can lead to depolarizing neuromuscular blockade
what is depolarizing neuromuscular blockade
when neurons are chronically stimulated and depolarized to the point that they cannot make and AP
what happens to the body in nerve gas / insecticide poisoning
cardiac arrest, fluid in lungs, bronchioconstriction, blockage of respiratory muscle contraction
what drug can be used to limit the effects of nerve gas
atropine
what are 4 conditions that cholinomimetics work well for
glaucoma
urinary retention
postoperative ileus
myasthenia gravis
what are cholinomimetics
muscarinic agonist or anticholinesterases
what causes myasthenia gravis
autoimmune disease with decreased nAChR expression at neuromuscular junction
what are the symptoms of myasthenia gravis
weakness, fatigue, difficulty opening eyes, respiration
how would you treat myasthenia gravis
anticholinesterases
what are 3 neuromuscular blockers (nicotinic antagonists)
succinylcholine
D-tubocurarine
α-bungarotoxin
what is succinylcholine
nicotinic antagonist/neuromuscular blocker, used for paralysis during surgery
what is D-tubocurarine
poison in blow darts, curari
what is α-bungarotoxin
protein in snake venom which causes paralysis
what is atropine
muscarinic antagonist
what causes parkinsons
excess cholinergic activity
lack of dopamine activity
how can atropine help with parkinsons
because antimuscarinics can help control with parkinsons tremors (lessens ACH cause parkinsons has excess)
what is scopolamine (drug class)
muscarinic antagonist
what can scopolamine treat
vestibular disturbances (motion sickness) -muscarinic antagonist
what do muscarinic antagonists do to cardiovascular system and why
drug like atropine would stop the parasympathetic breaks-increases HR, force of contraction
what do muscarinic antagonists do to respiratory system and why
slight bronchodilation and decreased secretion (block of parasympathetic tone)
what is ipratropium and what is it used for
muscarinic antagonist
COPD (chronic obstructive pulmonary disease)
what are directly acting sympathomimetics (definition)
α or β adrenoceptor agonists
what are directly acting sympathomimetics (examples)
adrenaline
noradrenaline
isoproterenol
what are indirectly acting sympathomimetics (definition+examples)
displace stored catecholamines from vesicles (amphetamines)
inhibit catecholamine reuptake (cocaine + TCAs)
what do alpha receptors have highest and lowest affinity for
A>=N»I
adrenaline stronger than noradrenaline thaaan isoproterenol
what do beta receptors have highest and lowest affinity for
I>A>=N
isoproterenol then adrenaline than noradrenaline
how to remember beta and alpha affinities
aggressive ANI (alpha) beaten IAN (beta)
what is vasomotor reversal
given adrenaline, BP goes up
given adrenaline with antagonist , BP goes down :0
what affinity do β1 receptors have for A vs NA
equal
what affinity do β2 receptors have for A vs NA
higher affinity for A than NA
what does prazosin do
blocks α1 adrenoceptors
what does yohibine do
blocks α2 adrenoceptors
are α or β receptors more sensitive to agonists
β are more sensitive to agonists
what is phenylephrine
α1 agonist (nasal decongestion)
what is clonidine
α2 agonist
what is isoproterenol (INA)
all β agonist
what is dobutamine
β1 agonist
what is salbutamol
β2 agonist (asthma puffer)
what is phentolamine
all α antagonist
what is prazosin
α1 antagonist
what is yohimbine
α2 antagonist
what is propanolol
allβ antagonist
what is metoprolol
β1 antagonist
what g protein pathway for α1 receptors
Gq
if α1 and M3 are both Gq, why do they have opposing effects on vascular smooth muscle?
M3 relax via receptors on endothelial cells that cause eventual NO release
α1 receptors are directly smooth muscle and cause it to contract
what G pathway for α2 receptors
Gi
what G pathway for β receptors
Gs
what happens in Gq
PLC increase IP3 and DAG
what happens in Gi
adenylyl cyclase is inhibited so less cAMP is made
what happens in Gs
adenylyl cyclase is activated so more cAMP is made
what does α1 do to blood vessels
vasoconstrict
what does α2 do to blood vessels
vasoconstrict
what does β do to blood vessels
vasodilate
how to remember G protein types for α1, α2, β
and blood vessel effect
goes q,i,s
like “kiss”
nervous nervous relaaaxed
vasoconstrict, vasoconstrict, vasodilate
