BIOL 319 Lecture: NMJ Physiology/Pharmacology

What is used to relax the airways during surgery?

acetylcholine antagonist

What does the neuron first do as far as the action potential goes?

originates AP which propagates down the axon

What does the AP do once the neuron fires it?

swims over Ca channels causing them to open: electrochemical gradient

Is calcium more on the inside or the outside of the axon terminal? 

outside 

What does calcium entering the axon terminal cause?

exocytosis of Acetylcholine from vesicles

What is acetylcholine made out of?

acetate and choline

What is the edge of the axon terminal also known as?

pre-synaptic membrane

What is the motor endplate also known as?

post synaptic membrane

What is the muscle cell also known as?

post-synaptic cell

What channels are located at the post synaptic membrane?

Acetylcholine gated sodium channels

Is sodium higher on the inside of the cell or the outside?

outside: why the inside is negative also known as polarization

What happens when Ach binds to the channels?

sodium enters which depolarizes the cell

What are two factors that keep the muscles from overreacting? 

Ach is not bound to the binding sites permanently 

Acetylcholine esterase breaks down Ach 

What would happen if Ach was permanently bound to the channel? 

muscle will permanently contract 

How does acetylcholine esterase break down Ach? 

uses water to cut ester bond with acetate and choline 

What ultimately controls overstimulation of the muscle?

the neuron

What is an example of an acetylcholine esterase inhibitor?

SARIN: nerve gas

What were the rules of the Geneva convention?

no torture of prisoners

no atomic weapons

no poisonous gas

What does SARIN do?

disables acetylcholine esterase permanently: causes maximal muscle contractions and inability to breath

Can SARIN be used clinically?

no: too strong