Exam 5 muscle paralytics

Question 1

What neurotransmitter does the somatic nervous system use?

Answer 1

acetylcholine

Question 2

What kind of receptor does the somatic nervous system use?

Answer 2

nicotinic

Question 3

Where is the cell body of somatic nerves located?

Answer 3

ventral horn of the spinal cord

Question 4

What kind of channel is the nicotinic receptor?

Answer 4

an ion channel (typically sodium)

Question 5

What activates nicotinic receptors?

Answer 5

nicotine and acetylcholine

Question 6

What does activation of nicotinic receptors result in?

Answer 6

Na influx, Depolarization, muscle action potential, opening of voltage-sensitive Ca2+ channel, release of calcium from sarcoplasmic reticulum, contraction

Question 7

Explain what nerve activation leads to?

Answer 7

Acetylcholine release > nicotinic receptor activation > muscle endplate depolarization > muscle action potential > calcium influx (from calcium channel) > calcium-induced calcium release (from SR) > calcium interacts with troponin > myosin-actin interaction (muscle contraction)

Question 8

What prolongs acetylcholine action?

Answer 8

anticholinesterases (neostigmine, pyridostigmine, edrophonium)

Question 9

What are anticholinesterases used for?

Answer 9

treatment of mysthenia gravis

Question 10

What is the action of neostigmine, pyridostigmine, and edrophonium?

Answer 10

anti cholinesterases

Question 11

What drug blocks acetylcholine release? What will this result in?

Answer 11

Botulinum toxin; prevents muscle depolarization and contraction

Question 12

What drugs block nicotinic receptors?

Answer 12

Mivacurium, tubocurarine (both competitive), succinylcholine (depolarizes)

Question 13

What blocks calcium-induced calcium release?

Answer 13

dantrolene

Question 14

What is useful in malignant hyperthermia? Why?

Answer 14

Dantrolene; will block contraction but not depolarization

Question 15

How does neostigmine, pyridostigmine and soman work?

Answer 15

indirectly stimulates nicotinic receptors by blocking Ach-ase action

Question 16

What is used to diagnose myasthenia graves? How does it work?

Answer 16

Edrophonium, reversible anticholinesterases

Question 17

What drug is used to treat potential nerve gas attacks?

Answer 17

soman

Question 18

What are the classic signs of anti cholinesterase toxicity?

Answer 18

SLUDGE (sweating, lacrimation, urination, diarrhea, GI disress, emesis)

Question 19

How does tubocurarine and mivacurium work?

Answer 19

competitive blocker of the nueromuscular jxn- not allowing sodium influx, depolarization and contraction

Question 20

How does succinylcholine work?

Answer 20

depolarizes end plate of muscle- chronic influx of Na+ causes depolarization and cannot repolarize itself

Question 21

What can block competitive neuromuscular blockers (tubocurarine)?

Answer 21

neostigmine, epinephrine and norepi have a slight ability to decrease the competitive blockade

Question 22

Where are competitive neuromuscular blockers (tubocurarine) most likely to act?

Answer 22

Jaw, eyes, limbs, diaphragm

Question 23

Where are neuromuscular depolarizing agents (succinylcholine) most likely to act?

Answer 23

chest and abdomen

Question 24

What can the toxic effects of succinylcholine be? How do you treat it?

Answer 24

Malignant hyperthermia, dantroline

Question 25

True/false: Mivacurium is long acting?

Answer 25

False; it's short acting

Question 26

What should you avoid giving to burn patients?

Answer 26

Succinylcholine (burned muscle increases concentration of nicotinic receptors, which will result in excessive potassium release in response to stimulation)

Question 27

What is the exact molecular action of botulinum toxin A?

Answer 27

prevents acetylcholine release by cleaving proteins necessary for acetylcholine exocytosis (blocks docking of vesicles)

Question 28

What can you use to potentiate contraction for myasthenia gravis?

Answer 28

anticholinesterases: Neostigmine, pyridostimine, edrophonium

Question 29

What drug prevents contraction and malignant hyperthermia?

Answer 29

dantroline (calcium chelator)

Question 30

What drugs paralyze the patient by being nicotinic receptor antagonists?

Answer 30

Competitive: tubocurarine, mivacurium, Depolarizing: succinylcholine

Question 31

What can you use to paralyze patients muscles by preventing acetylcholine release?

Answer 31

botulinum toxin

Question 32

How does succinylcholine act?

Answer 32

Depolarizes by causing constant Na+ influx into cell

Question 33

What potentiates the action of succinylcholine?

Answer 33

Anticholinesterases- increase the amount of acetylcholine in the junction, thereby also increasing the amount of Na+ that influxes into the cell

Question 34

T/F: treatment of burn patients with succinylcholine is perfectly safe for intubation

Answer 34

FALSE. Will prop open nicotnic receptors which will lead to potassium leaking outside of the cell, increasing extracellular concentrations