muscle contraction quiz

Question 1

impulse comes down axon of neuron due to a stimulus received

Answer 1

1

Question 2

When impulse reaches axonal terminals vesicles located there release a neurotransmitter called acetylcholine

Answer 2

2

Question 3

ACh goes across the synaptic cleft and binds to ACh binding sites on the sarcolemma

Answer 3

3

Question 4

Binding of ACh causes sodium channels to open so membrane is permeable to sodium ions

Answer 4

4

Question 5

Sodium ions rush into the cell from the interstitial lfuid and causes a positive charge inside the cell causing an action potential

Answer 5

5

Question 6

Action potential causes calcium ions to be released from the sarcoplasmic reticulum

Answer 6

6

Question 7

Calcium binds to binding site on actin

Answer 7

7

Question 8

Once calcium binds- myosin head binds to to actin too. Pulls actin towards center of sarcomere to cause a contraction

Answer 8

8

Question 9

When action potential ends, calcium releases from actin, myosin heads release from actin, potassium gets pumped outside to bring electrical potential back to normal

Answer 9

9

Question 10

later, sodium and potassium pump used to get sodium back outside and potassium back insside

Answer 10

10

Question 11

Contraction - can start again

Answer 11

11

Question 12

Irritability

Answer 12

Ability to receive and respond to stimuli

Question 13

Contractility

Answer 13

Ability to shorten if stimulated

Question 14

Motor unit

Answer 14

One neuron and all the skeletal muscle cells it stimulated

Question 15

Neuromuscular junction

Answer 15

Where axon of a neuron and sarcolemma meet

Question 16

Myosin

Answer 16

Thick filaments

Question 17

Actin

Answer 17

Thin filaments

Question 18

Graded response

Answer 18

Different degrees of shortening