LECTURE 12 & 13: AUTONOMIC Flashcards
fight or flight (CVS, Respiratory and Miscellaneous)
CVS - ^ HR, ^ myocardial contraction strength, vasodilation
Respiratory- ^ respiratory rate, bronchioles dilate
Miscellaneous - mydriasis, ^BGC, decrease GIT motility
receptor of sympathetic nervous system
adrenergic receptors
adrenergic agonist
adrenaline/ epinephrine
noradrenaline
dopamine
pseudoephedrine
phenylephrine
solbutamol, salmeterol, clenbuterol
main adrenergic agonist
adrenaline / epinephrine
adrenergic receptor types
alpha 1 + 2
beta 1 + 2
Alpha 1 adrenergic receptor
- vasoconstriction to ^bp
- pupils dilate
- reduced GIT motility
- Splenic contraction
- bladder sphincter contraction
Alpha 2 adrenergic receptor
- vasoconstriction and vasodilation
- CNS effects
Beta 1 adrenergic receptor
- ^ myocardial contraction and ^ HR = ^ CO
- detrusor muscle relaxation
A1 receptor mainly concerned with
blood vessels
B1 receptor mainly concerned with
heart
B2 receptor mainly concerned with
lungs
Beta 2 adrenergic receptor
- bronchiolar dilation
- vasodilation in skeletal muscle
what receptor is responsible for vasodilation at skeletal muscle
B2
use of adrenaline in emergency
anaphylaxis e.g. epipen
what does adrenaline do in anaphylaxis in concern to adrenergic receptors
- reverses effects of histamine by acting as physiological antagonist
- reverses fatal bronchiolar constriction by B2 antagonism
- reverses vasodilation by A1 vasoconstriction (at skin)
adrenaline acts as what kind of antagonist in anaphylaxis
physiological antagonist
route of epipen amdinistration
IM
Does noradrenaline work same as adrenaline
yes
dopamine as an adrenergic agonist at low, high and high still doses
low - acts on dopamine receptor = erection
high - B1 = ^ cardiac contraction
high still dose - A1 = systemic vasoconstriction
Name a drug used to relieve nasal congestion
Pseduoephedrine and phenylephrine
phenylephrine has replaced as major because pseudo has CNS effects
how do nasal decongestant drugs work
A1 vasoconstriction
has phenylephrine been used for nose bleeds
yes
Solbutamol, salmeterol and clenbuterol are primarily used for ______ support owing to their ___ receptor _____
respiratory
B2
agonism
adrenergic antagonists
prazosin and beta blockers
prazosin as an antagonist
A1 antagonist = vasodilation
propranolol and atenolol antagonists act as ____________ and ________ due to their effect of excessive sympathetic stimulation, owing to their ______ antagonist effects
antiarrhythmic and vasodilator
beta
which beta-blocker should be used with caution with airway disease
propanolol because targets both beta-adrenergic receptors
Cholinergic receptors respond to ________ and includes _______ & _______
acetylcholine
nicotinic acetylcholine receptor
muscarinic acetylcholine receptor
nicotinic acetylchoine agonists
Ach and nicotine
nicotinic acetylcholine antagonist
tobucurarine
muscarinic acetylchoine antagonist
atropine / hyoscine
muscarinic acetylcholine agonist
muscarine
rest and digest (CVS, Respiratory, GIT, Misc)
CVS - dec HR
Res - bronchiolar constriction
GIT - ^ motility, salivation, sphincters open
Misc - pupils contract, lacrimation
excessive ACh (PNS and somatic) signs (muscarinic, somatic and CNS)
muscarinic - salivation, lacrimation, urination, vomiting
somatic - muscle tremor
CNS - seuziring
Parasympathomimetics
drugs that have similar effects as PNS activation
example of Parasympathomimetic and what it does
bethanocol, ^ GIT motility
Parasympatholytics
drugs that inhibit PNS
Parasympatholytics are __________at the _________ acetylcholine receptor
antagonists
muscarinic
Parasympatholytic examples
atropine, tropicamide, ipatropium, hysoscine
important example of Parasympatholytics and its use
atropine, used to dilate pupil in eye examinations
parasympatholytic toxicty little saying
dry as a bone, red as a beet, mad a a hatter
dry as a bone due to ___________, red as a beet due to ________, and mad as a hatter due to _____
Dec sweat, saliva, lacrimaiton
dec sweating and hyperthermia
CNS effects
compare mydriasis with atropine and tropicamide
Tropicamide has short onset and shorter duration
atropine has longer onset and longer duration
drugs with nicotinic like effects are also called ___________ and includes the examples __________
cholinesterase inhibitors
neostigmine, edrophonion, organosphosphate
main cholinesterase inhibitor to remmeber is
neostigmine
what drugs are used for myasthenia gravis
cholinesterase inhibitors
drugs with antinicotinic effects are our
NM blockers
NM blocker example
atracurium
Describe how neostigmine acts as an antidote for atracurium
Neostigmine is an acetylcholinesterase inhibitor that prevents the breakdown of ACh. This causes the concentration of ACh in the neuromuscular junction to increase to a point that overcomes the competitive antagonism of the atracurium on the muscle’s nicotinic receptors.
why use NM blockers
surgery
atracurium is a competitive ____________ which gains access to ____ and antagonises the action ACh can _________
nicotinic receptor antagonist
Ach R
have on receptor
cholinesterase inhibitors do what?
decrease the breakdown of acetylcholine
