How Muscle Fibers Contract- HOW NERVES CAUSE MUSCULAR CONTRACTION - Use of Neurotransmitter in Muscle Contraction

Question 1

There is a sequence of events that happen when the use of a neurotransmitter in muscle contraction. What are 1 through 4?

Answer 1

1) Electrical impulse (Action potential) in nerve reaches 
the presynaptic terminal.
2) Calcium channels open, causing Ca+
to enter the
presynaptic terminal.
3) Presynaptic vesicles release acetylcholine (ACh) into 
the synapse.
4) Acetylcholine crosses the synapse.

Question 2

There is a sequence of events that happen when the use of a neurotransmitter in muscle contraction. What are 5 through 8?

Answer 2

5) Acetylcholine binds to ACh receptors (sodium
channels) in the postsynaptic terminal (in muscle
fiber).
6) Sodium channels open, causing Na+
to enter.
7) An electrical impulse has now been started in the
muscle fiber.
8) Acetylcholine remains in the synapse only briefly.
It is broken down by the enzyme cholinesterase
(AChE) and returned to the presynaptic vesicles to be
reused.

Question 3

neurotransmitters =

Answer 3

Acetylcholine (ACH)

Question 4

What is Cholinesterase known as?

Answer 4

“hatchet” / enzyme that breaks ACH apart