peripheral nervous system L10-13 Flashcards
autonomic
controls smooth muscle and glands
involuntary
either sympathetic/ parasympathetic
somatic
motor innervation of skeletal muscles
voluntary
synthetic enzyme needed for ACh
CAT
chlineacetyl transferase
ACh receptor types
nicotinic
muscarinic
metabolic enzyme for ACh
acetylcholinesterase breaks down into choline + acetate
muscarinic ACh receptor
post-ganglionic parasympathetic synapses
G-protein coupled
7 transmembrane spanning
slow
nicotinic ACh
sym/para excitatory
NMJ
ligand-gated
4/5 sub-unit structure
ion channel coupled
fast
muscarinic agonist example
carbachol/ pilocarpine
(glaucoma treatment via ciliary muscle contraction)
(xerostomia treatment w saliva secretion stimulation)
muscarinic antagonist example
atropine-like drugs (pupil dilation/ decrease in oral/ resp secretions)
atropine> bradychardia resus
hyoscine > motion sickness
ipatropium > asthma
neuronal nicotinic agonists
activate symp and para systems
excitatory of brain and autonomic ganglia
not clinically useful as autonomic confusion occurs
neuronal nicotinic agonist example
suxemethonium
paralysis/ muscle relaxation
neuronal nicotinic antagonist example
tubocurarine
hyperpolarization/ EPP inhibition
muscle fibre relaxation and paralysis
noradrenaline receptors
alpha/ beta
NA production process
tyrosine > DOPA > DA> NA
(tyr hydroxylase) (DOPA decarboxylase) (DA B-hydroxylase)
NA reuptake
monoamine oxidase breakdown into amines
NA synthesis/ storage/ release/ receptor interaction/termination
tyrosine/ tyrosine hydroxylase etc
vesicle storage
exocytotic release
a/b receptor interaction
terminated via uptake/ recycle via monoamine oxidase
noradrenergic receptors
a1/ a2
b1/ b2/ b3
metabotropic
slow
a2
presynsaptic
inhibits neurotransmitter release
a1
mediate sympathetic effects
b1 effects
^HR
B2 effects
bronchodilation
B3 effects
^lipolysis
NA agonists
adrenaline
dobutamine
salbutamol
clenbuterol
adrenaline agonist NA effect
all NA (vasoconstriction/ smooth muscle contraction/ cardiac stimulation/ bronchial smooth muscle relaxation)
gut breakdown
clonidine
a2 agonist
hypertension treatment
reduces NA release
dobutamine
selective B1 agonist
^ cardiac rate/ force
treats heart failure