Week 8: The Muscular System

Question 1

What are the three types of muscle?

Answer 1

Skeletal Cardiac Smooth

Question 2

Are smooth muscles and cardiac muscles voluntary?

Answer 2

No they are involuntary

Question 3

Are smooth muscles striated?

Answer 3

No

Question 4

Are cardiac muscle striated?

Answer 4

Yes

Question 5

What are the functions of skeletal muscle?

Answer 5

Contractions Metabolism Heat generation Amino acid store

Question 6

What are the properties of skeletal muscle?

Answer 6

Contractility Excitability Extensibility Elasticity

Question 7

How is skeletal muscle connected to the skeletal?

Answer 7

Via tendons

Question 8

What is the composition of skeletal muscle?

Answer 8

75% water 20% protein 5% salts and other substances

Question 9

What are the three types of muscles arcitecture?

Answer 9

Parallel Unipennate Multipennate

Question 10

How many motor neurons innervate each muscle fibre?

Answer 10

Only one

Question 11

What is action potential?

Answer 11

The rapid rise and fall of a cells electrical membrane potential

Question 12

What does action potential provide?

Answer 12

The electrical stimulus for muscle contraction

Question 13

In order for the muscle to contract what must the level of stimulus cross?

Answer 13

A threshold

Question 14

What regulate action potential?

Answer 14

The sodium potassium pump

Question 15

What happens to the muscle contraction if the stimulus doesn’t pass the threshold?

Answer 15

Failure to contract

Question 16

In the sodium potassium pump what enter and leaves the cell?

Answer 16

Sodium enters Potassium leaves

Question 17

What happens to the membrane potential after action potential has bee reached?

Answer 17

It decreases during the re-polarisation period and then decreases below resting state during the refractory period

Question 18

Where in the muscle is calcium released from?

Answer 18

Sarcoplasmic reticulum

Question 19

Where does the action potential spread?

Answer 19

Down the sarcolemma, reaching transverse tubules (T-tubules)

Question 20

What happens when calcium is released into the cell?

Answer 20

It binds to troponin on the thin filament therefore enables myosin to bind to actin

Question 21

At rest, what binds to the myosin head and why?

Answer 21

ATP to release energy that promotes myosin head into an extended, high energy position

Question 22

What does the extended myosin bind to?

Answer 22

The active site on the actin molecule (called a cross bridge)

Question 23

When the myosin had bound to the actin molecule what is released and why?

Answer 23

ADP is released to tug the actin towards the centre of the sarcomere

Question 24

What is needed to break the cross bridge?

Answer 24

A new ATP molecule

Question 25

How are type 1 muscle fibers adapted for aerobic respiration?

Answer 25

Large blood supply High myoglobin content Large aerobic metabolism

Question 26

How are type 2 muscle fibers adapted for anaerobic metabolism?

Answer 26

Less blood supply, myoglobin and mitochondria High content of glycogen and glycolytic enzymes

Question 27

What is the functions of satellite cells?

Answer 27

To prevent nuclear dilution

Question 28

Label the diagram

Answer 28

1. Z discs
2. Thin filament
3. Thick filament
4. M line
5. Thin filament
6. Z disc
7. I band
8. Zone of overlap
9. Sarcomere
10. H zone
11. A band