ANS Flashcards
(28 cards)
Output of SNS
T1-L2
Effects of PSNS
Miosis, increased secretion, decreased HR, constricts bronchi, increased peristalsis, contract bladder
Effect of SNS
Mydriasis, decrease secretion except saliva and sweating, increase HR, dilates bronchi, inhibit peristalsis, inhibit bladder, eyelid open, NA and A secretion
Effect of horners syndrome (neck symp chain damaged on one side)
Miosis, anhidrosis, ptosis
Innervation of blood vessels
Sympathetic
Innervation of ciliary eye muscles
Only parasympathetic
Where does PSNS dominate
GIT, bladder, salivary glands
Common features of SNS and PSNS
Cell bodies in lateral horn, 2 axons, Ach at ganglionic synapses nAChR.
Features of PSNS transmission
Long preganglionic axon, short post, 1:3 pre post ratio.
Features of SNS transmission
Short preganglionic axon, long post, 1:10 ratio
PSNS post ganglionic neurotransmitter and receptor
Ach and mAChR
SNS post ganglionic neurotransmitter and receptor
NA and adrenoceptor
neurotransmitter and receptor at adrenal medulla
Ach and nAChR
What type of receptor is nAChR
Ionotropic, pentameric, alpha 3
What activates nAChR
Nicotine, ACh
What type of receptor is mAChR
Metabotropic, monomeric, GPCR, m1-m5
What activates and deactivates mAChR
Muscarine and Ach
Atropine blocks
What type of receptors are adrenoceptors
Metabotropic, alpha 1,2 beta 1,2,3
What activates adrenoceptors
NA, A, isoprenaline
Subunits of nAChR
Alpha, beta, delta, epsilon, gamma
Action of nAChR
2ACh bind. Na in, K out -> depolarisation
NAChR subtypes where
Ganglia alpha 3. AM and NMJ alpha 1
Mechanism of metabotropic/GPCR
A binds to R, GP binds to RA, GDP displaced by GTP, beta gamma and alpha split. Activate of inhibit E. GTP hydrolysed to GDP, su’s rejoin
Activation of PLC
Gq - PLC forms DAG, stims PKC, phosphorylates. Also forms IP3 stimulates R on ER, efflux of Ca
