A 11 Neuromuscular Junction Flashcards
what is the name of the enzyme that makes acetylcholine, and what two compounds come together to make the acetylcholine?
Cholineacetyltransferase. The two parts that make up acetylcholine are choline and acetyl CoA.
what is required to activate the nicotinic acetylcholine receptor?
2 X acetylcholine molecules.
what causes repolarization?
It is due to the closure of the voltage gates Na+ channels and the opening of the voltage gates K+ channels.
what is the active zone of a neuron?
the area of the presynaptic terminal where exocytosis of acetylcholine occurs
what is Agrin?
a proteoglycan released by the neuron that helps to form the normal neuralmuscular junctions.
what is Eaton-Lambert syndrome?
an autoimmune disease that targets the voltage gated calcuim channel on the nerve terminal. You see an increase in muscle tension with stimulation.
what is a MEPP?
MEPP stands for miniature end-plate potential. It is when the neuron spontaneously releases one quanta which causes a very small stimulus.
What is MUSK?
muscle specific kinase. A receptor that is responsible for the clustering of nicotinic receptors on the muscle fiber. Agrin binds/stimulates it.
what is myasthenia gravis?
an autoimmune disorder attacking the nicotinic ACh receptors on muscles. You see a decrease in muscle tension with continues stimulation.
What drugs work as agonists to the nAch receptor?
Nicotine and carbachol
Which drug is used to block the nAch receptor?
Curare and bungarotoxin
Name 3 drugs that block acetylcholine activity?
DFP, neostigmine, physostigmine
What is hemicholinium?
A drug that blocks the reuptake of choline into the neuron.
Name the two toxins that block the Na+ channels on both the muscle and the neuron?
Tetrodotoxin and saxitoxin.
MuSK and rapsyn from the muscle are expressed to help localize the motor end plate connections with the nerve. What 3 things does the nerve release in order to help with this connection?
Agrin (binds to MuSK)
Neuregulin
Acetylcholine
