Lecture 8: ANS Neuromuscular Blockers

Question 1

each somatic neuron of the neuromuscular junction has many presynaptic boutons that create localized regions where ___ is released in close proximity to the ____ receptors on the other side of the synapse

Answer 1

Ach, Nm Ach

Question 2

Nm Ach receptors are a specific nictonic subtype receptor only. found at the ____

Answer 2

neuromuscular jucntion

Question 3

activation of Nm Ach receptors causes membrane ___ leading to ___

Answer 3

depolarization, muscle contraction

Question 4

in the case of muscles, breakdown of ach causes ___

Answer 4

muscle relaxation

Question 5

when ach binds to the Nm receptor there is an influx of ___ ions

Answer 5

Na

Question 6

____ breaks down Ach, which allows channels to close, causing membrane to be ___

Answer 6

ache; repolarize

Question 7

prolonged activation of Nm receptors leasd to ___

Answer 7

muscle paralysis

Question 8

what 3 things can cause muscle paralysis at Nm receptors?

Answer 8

1. organophospahte
2. nerve gas
3. nicotine overdose

Question 9

if Nm channels are not activated it can have a ___ effect

Answer 9

paralytic

Question 10

_____ are used in conjunction with anesthesia in surgery to prevent muscle contraction and achieve temporary paralysis

Answer 10

neuromuscualr blockers

Question 11

wha are the 2 main types of neuromuscular blockers?

Answer 11

1. depolarizing

2. non-depolarizing

Question 12

what is the role of Nm antagonsits?

Answer 12

prevent passing of ions through the channel, preventing muscle contractio

Question 13

what is the classic exampleof non-depolarizing neuromuscualr blocker?

Answer 13

tubocuranine

Question 14

what is tubocurarine the derivative of?

Answer 14

a natural product used by hunters of native tribes to paralyze prey

Question 15

what happens to Ach binding in the presence of tubocurarine?

Answer 15

unable to bind to Nm receptor and channel remains closed

Question 16

tubocurarine is a ___ of the Nm receptor

Answer 16

competitive antagonsist

Question 17

the paralytic effects of tubocurarine can be reversed by increasing ___ . Thsi can be done by adding ____ inhibitor

Answer 17

adding more Ach to the synaptic cleft ; ache

Question 18

what is an example of a depolarizing neuromuscular blocker?

Answer 18

succinylcholine

Question 19

succinylcholine binds to ion channels once they have alredy ___

Answer 19

opened

Question 20

succinylcholine is a ___ of the Nm receptor

Answer 20

competitive antagonist

Question 21

what is the effect of succinylcholine binding to channels once they are already open?

Answer 21

preliminary depolarization and muscle contraction

Question 22

describe the “depolarization block” caused by succinylcholine

Answer 22

becease cells cannot rapidly repolarize, they are held in a refractory state that will not respond to furthe stimuli

Question 23

as long as succinylcholine is bound to the receptor, the cells may slowly ___ over several minutes, but ___ will be delayed

Answer 23

repolarize, reactivation and contraction

Question 24

is succinylcholine reversible or irreversible

Answer 24

reversible

Question 25

because the blocking effect of succinylcholine is acheived by holding the channel open, the block cannot be ___ inhibited using ache inhibitors

Answer 25

competively

Question 26

botulinum toxin binds to the ___ complex, preventing the release of ___

Answer 26

SNAP; Ach

Question 27

botulinum toxin is a ____ toxin that interferes with the process of ___

Answer 27

bacterial; exocytosis of Ach vessicles

Question 28

systemic exposure of botulinum toxin causes ____ and ___ but local administration is used to treat ___ and ___

Answer 28

paralysis and death; wrinkles, migraine pain

Question 29

does botox interact with cholinergic receptors directly? What type of antagonist does this make botox?

Answer 29

No; indirect