Muscle Contration

Question 1

What is the first step of the muscle contraction process

Answer 1

Nervous impulse arrives at the synaptic knob

Question 2

Once the nerve impulse arrives at the synaptic knob ______ enters the synaptic knob which triggers the release of ________

Answer 2

Calcium enter the synaptic knob which triggers the release of acetylcholine

Question 3

Once ACh is released from the synaptic knob it

Answer 3

enters the synaptic cleft and binds to receptors on the muscle cell motor end plate

Question 4

Where is the muscle cell motor end plate

Answer 4

sarcolemma

Question 5

The binding of ACh to the muscle cell motor end plate results in

Answer 5

depolarization of the sarcolemma

Question 6

Once the sarcolemma is depolarized the impulse travels along

Answer 6

the sarcolemma and through the T-tubules

Question 7

Impulse reaches the sarcoplasmic reticulum which causes the release of _________ which spreads ______

Answer 7

calcium which spreads throughout the cell

Question 8

Calcium then binds to ______ on the thin myofilament

Answer 8

troponin

Question 9

When calcium binds to troponin on the thin myofilament

Answer 9

tropomyosin is displaced and binding sites on actin are exposed

Question 10

When does the cross bridge form

Answer 10

when myosin binds to actin

Question 11

Sarcomeres _____ when filaments slide past one another and muscle contracts

Answer 11

shorten (sliding filament theory)

Question 12

What are the 4 stages of cross-bridge cycling

Answer 12

1. Attach 2. Pivot 3. Detach 4. Reset

Question 13

Attach

Answer 13

Myosin bonds to actin

Question 14

Pivot

Answer 14

Myosin pulls thin filament toward each other

Question 15

Detach

Answer 15

ATP attaches to myosin and myosin head detaches

Question 16

Reset

Answer 16

Actin and myosin go back to original positions