autonomic nervous system 4

Question 1

basic principles of Neurotransmission for cholinergic synapse

Answer 1

Ach synthesis from choline and acetyl coa using CAT
choline taken up by the terminal (limiting factor)
synthesis of ach determined by choline uptake
actively packaged
requires a proton gradient

Question 2

synthesis of adrenergic nt noradrenaline and

rate limiting step =

Answer 2

ATP

conversion of tyrosine

Question 3

drugs that affect Ach synthesis/packaging

Answer 3

Hemicholinium - inhibits choline uptake
vesamicol - inhibits Ach packaging
no clinical use

Question 4

what can we uses drugs that affect Ach synthesis and packaging for

Answer 4

use them to dissect the transmission seeing the impact of the transmission in certain cells

Question 5

ach release how much and how much is used

Answer 5

3 million released from 1 neurone of 300 vesicles
2 million released and act on 1 of the 30 million receptors
only 2ms then hydrolysed by AchE on the NMJ

Question 6

drugs affecting Ach release

Answer 6

streptomycin/neomycin - inhibits Ca influx, reduces NT release
botulinum toxin and Beta bungrutoxin - cleaves protein involved in vesicle exocytosis

Question 7

regulation of Ach release

what happens with the post ganglionic synapse

Answer 7

M2R found presynaptically

ach acts on it and inhibits Ach release

Question 8

regulation of Ach release

at the NMJ terminals what happens

Answer 8

Ach acts presynaptically on nAchR to enhance further Ach release

Question 9

regulation of Ach release

in the CNS terminal what happens

Answer 9

nAchRfound presynaptically to increase or decrease release of NT such as glutamate and Dopamine

Question 10

Ach inactivation

what is it broken down by

Answer 10

AchE

or BuchE

Question 11

ach inactivation

what does AchE do

Answer 11

it hydrolysis Ach within 2ms of interaction with receptor

tethered to cleft

Question 12

inhibition of Ach what happens

Answer 12

allows more then one receptor to be bound and activated

helps in altzimers

Question 13

drugs that affect breakdown (enhhance cholinergic transmission)

Answer 13

Neosigmine - inhibits AchE breakdown at NMJ
physostigmine - inhibits ACHE acting at post ganglionic cholinergic synapses
donezapil - inhibits ACHE at CNS cholinergic synapse

Question 14

Nicotinic receptors where are they used

Answer 14

ganglionic - post
CNS - pre
NMJ - post

Question 15

drugs that act at nicotinic

Answer 15

nicotine- ganglionic and CNS stimulant
hexamethonium (antagonist) -autonomic ganglion blocker
blood pressure lowering agent
tubocurarine - NMJ blocker
muscle relaxant

Question 16

muscurinic receptors where are they used M1 M2 and M3

Answer 16

M1 - CNS glanglia -CNS excitation
M2 - heart/ CNS cardiac and presynaptic inhibition because of decrease ca2+
M3 - glands/smooth muscle - increase Ca2+ influx causing excitation

Question 17

drugs that affect muscurinic r

7 answers

Answer 17

agonists- muscurine/carbachol - non selective - glaucoma
antagonists- atropine/tiotropium - parasynpatholysis,
inhibition of secretions
tachycardia
bronchodilation in asthma
pupillary dilation