Neuromuscular blockade

Question 1

What is muscle force in a single myocyte regulated by

Answer 1

frequency of action potentials

Question 2

What does a person experience during a neuromuscular blockade

Answer 2

Slow methodical paralysis in skeletal muscle

• first extrinsic muscles of eye
• then small muscles of face and hands

Question 3

How can we block neuromuscular transmission

Answer 3

stop;
synthesis
release
receptor
reuptake-inactivation

Question 4

What is synthesis blocking

Answer 4

After there is a conversion of ach into choline and acetate, the choline carrier takes choline back into the presynaptic bouton
-choline acetyltransferase converts choline into ach

synthesis blocking is when Hemicholonium stops the choline carrier from taking choline back to ps bouton

Question 5

What converts choline into ach

Answer 5

acetyltransferase

Question 6

What is used to stop synthesis of ach

Answer 6

Hemicholonium

Question 7

What happens when release is inhibited

Answer 7

Ach goes to vesicle for release

• vesamicol stops the uptake of ach into vesicle
• presynaptic toxins like botulinum stops the docking on vesicles on membrane

Question 8

What is vesamicol used for

Answer 8

Stops the uptake of ach into vesicle

Question 9

Whats botulinum

Answer 9

Stops the docking of vesicles on membrane

Question 10

Whats an example of a non depolarizing blocking agent

Answer 10

Tubocurarine

Question 11

Whats an example of a depolarizing blocking agent

Answer 11

Suxamethonium (cause opening of pore)

Question 12

Whats an agonist

Answer 12

Any compound that binds to a receptor and activates it

Question 13

Whats an antagonist

Answer 13

Any compound that binds o a receptor and deactivates it

Question 14

Whats a competitive antagonist

Answer 14

Competes with the the natural agonist for receptor binding sites

Question 15

Whats an example of an anticholinesterase

Answer 15

Neostigmine

Question 16

What drugs are available for increasing inactivation

Answer 16

NO drugs are available to increase inactivation, but blockade of inactivation is used to reverse neuromuscular blockade

Question 17

Whats an achE inhibitor

Answer 17

Physostigmine (reverse antagonist block)

Question 18

Why does myasthenia gravis come about

-What drugs are used to treat this

Answer 18

Prouction of autoantibodies against the nicotinic AChR

-anticholinesterase inhibitors eg pyridostigmine

Question 19

What are two classes of neuromuscular blockers

Answer 19

Non Depolarising

Depolarizing

Question 20

What do non depolarizing blockers do

Answer 20

nACh-R antagonists

Question 21

What do depolarizing blockers do

Answer 21

nACh-R agonists (mimic aCh)

Question 22

Names of non-depolarizing blockers

Answer 22

• atracurium
• vecuronium
• tubocurarine
• gallamine
• alphabungarotoxin

Question 23

Names of depolarizing blockers

Answer 23

• Suxamethonium

- Decamethonium

Question 24

Features of non-depolarizing block

Answer 24

• Occupy without stimulating post-synaptic each receptors
• Additive effect of similar drug
• block is competitive
• BLock not preceded by stimulation

Question 25

What happens during a non-depolarizing block

Answer 25

High frequency stimulation causes tetanus with duration only slightly longer than a twitch

Question 26

What is a non-depolarising block antagonized by

Answer 26

Agents that depolarize muscle membrane

Question 27

What is non-depolarizing block antagonized by also

Answer 27

Drugs that increase ACh release (e.g. adrenaline)

Question 28

What is a non-depolarizing block reversed by

Answer 28

anticholinesterases e.g. neostigmine

Question 29

what do depolarizing blockers do

Answer 29

Persistent activation of nACh-R causes inactivation of voltage-gated Na+ channels i.e. can no longer open in response to brief depolarization

Question 30

Example of depolarizing blocker

Answer 30

Suxamethonium (nACh-R agonist)

Question 31

Examples of nAC-r antagonists (non-depolarizing blockers)

Answer 31

- Atracurium - Vecuronium - Gallamine

Question 32

Examples of nAC-R agonists (depolarizing blocker)

Answer 32

- Suxamethonium | - Dexamethonium

Question 33

Examples of Acetylcholinesterase inhibitors

Answer 33

- PHysiostigmine | - Neostigmine

Question 34

Features of non-depolarizing blockers

Answer 34

- Slower onset and longer duration - useful in surgery - Reversible with antiAChE drugs

Question 35

Features of depolarizing blockers

Answer 35

- rapid onset and offset - FAst onset, short duration - Useful in tracheal intubation, ECT, dislocations

Question 36

Which blockers are useful for surgery

Answer 36

Non-depolarising

Question 37

Which blockers have a rapid onset and offset

Answer 37

depolarizing

Question 38

Which blockers are reversible with antiAChE drugs

Answer 38

Non-Depolarizing