excitation of skeletal muscle (midterm 1)

Question 1

what does the nerve fiber form

Answer 1

branching nerve terminals that go into the surface of the muscle fiber and are outside the muscle fiber plasma membrane

Question 2

what is the structure of the nerve fiber called

Answer 2

motor end plate

Question 3

what surrounds the axon

Answer 3

myelin sheath

Question 4

what are the safety factors of excitation of skeletal muscles

Answer 4

end plate potential < threshold => rarely fatigue

Question 5

what’s the end plate potential

Answer 5

local potential caused by Na+ flux

Question 6

what is curate

Answer 6

a drug that blocks the gating action of acetylcholine on the acetylcholine channels by competing for the acetylcholine receptor sites

Question 7

what is botulinum toxin

Answer 7

a bacterial poison that decreases the quantity of acetylcholine release by the nerve terminals

Question 8

when is Ca++ too low for A-M binding

Answer 8

normal - ~10^-2 M

Question 9

when is Ca++ 10x higher than needed

Answer 9

excitation - ~20^-2 M

Question 10

when does muscle contraction occur

Answer 10

during Ca++ alone and continuous contraction requires continuous Ca++ release