Pharma - Neuromuscular junction

Question 1

features of the ANS

Answer 1

involuntary - glands, cardiac tissue, metabolic activity
regulated by brain stem centres

Question 2

features of the SNS

Answer 2

voluntary body movements
regulated by corticospinal tracts and spinal reflexes

Question 3

where are the neuromuscular junctions of the para and sympathetic NS located

Answer 3

parasympathetic - postganglionic neurone
sympathetic - preganglionic neurone

Question 4

outline acetylcholine synthesis

Answer 4

pyruvate dehydrogenase converts pyruvate into acetyl-CoA and choline
cholineacetyltransferase converts that into acetylcholine

Question 5

what converts ACh into acetate + choline

Answer 5

acetylcholinesterase

Question 6

features of acetylcholine

Answer 6

requires 2 ACh to activate
5 different sub-types:
alpha, beta, gamma, delta, epsilon

Question 7

how many types of Nm receptors are there

Answer 7

alpha1
beta1
delta
gamma
epsilon

Question 8

how types of Nn receptors are there

Answer 8

alpha2-10
beta2-4

Question 9

what causes grave muscle weakness (myasthenia gravis)

Answer 9

autoantibodies bind to nicotinic AChR on the motor end plates of muscle

Question 10

how does autoantibodies binding to MuSK contribute to myasthenia gravis

Answer 10

prevents ACh from clustering at the neuromuscular junction

Question 11

what causes Lambert-Eaton myasthenic syndrome

Answer 11

autoantibodies binding to voltage gated calcium channel

Question 12

outline Lambert-Eaton myasthenic syndrome

Answer 12

interferes with calcium-dependent ACh release
reduced endplate potential at the post-synaptic membrane
results in NMJ transmission failure

Question 13

what occurs when autoantibodies bind to voltage gated potassium channels

Answer 13

neuromyotonia (Isaac’s syndrome)

Question 14

outline neuromyotonia

Answer 14

autoantibodies that bind to the K+ channels on motor nerve endings
results in hyper excitability

Question 15

function of vesimicol

Answer 15

inhibits storage of ACh to the vesicle

Question 16

function of hemicholinium

Answer 16

competes with choline for uptake

Question 17

name 2 neuromuscular block reversal agents and their function

Answer 17

neostigmine - increases junctional concentration of ACh
suggamadex
both - reversal of non-depolarising block

Question 18

what are non-depolarising neuromuscular blocking agents and their function

Answer 18

tubocurarine
pancuronium
vecuronium
competitive ACh receptor antagonists

Question 19

name depolarising neuromuscular blocking agents and their function

Answer 19

decamethonium
succinylcholine
mimic ACh

Question 20

what is neostigmine

Answer 20

anticholinesterase
blocks the action of AChE
increase junctional ACh concentration

Question 21

what is a cholinergic crisis

Answer 21

overstimulation of the NMJ leads to insensitivity to ACh

Question 22

how do you cure a cholinergic crisis

Answer 22

atropine

Question 23

what chemical group is an irreversible AChE inhibitor and how

Answer 23

organophosphates
phosphate covalently binds to a serine hydroxyl group in the active site of AChE

Question 24

name a competitive inhibitor of AChE

Answer 24

edrophonium

Question 25

what is physostigmine

Answer 25

a reversible pseudo-competitive AChE inhibitor

Question 26

name an antispasmodic and its function

Answer 26

botulinum toxin
blocks release of ACh