Skeletal Muscle Physiology Worksheet

1. What percent of the body is smooth muscle? Striated muscle?

40% of the body is striated muscle and 5-10% is smooth muscle

2. Name 3 types of muscle proteins. What is the function of each?

• Stroma Protein- its function is to hold the other structures in place.



• Cellular Protein- there isnt much of a specialized function since this protein is also found in other metabolically active cells.



• Contractile Protein- composed of two different proteins, myosin and actin. Its function is to make the contraction of muscles possible

3. What is a myofibril?

It is each independent, cylindrical element in a muscle.

4. Sketch a picture of a sarcomere. Label the I-band, the A-band, the Z-line and the H-zone.

5. Name the two filaments that make up a sarcomere.

Thick and thin filaments.

6. Draw a sarcomere at rest, contracted, and stretched .





























7. What is the sliding filament theory?

As the muscle becomes shorter due to increased contraction, the thick and thin filaments slide past each other, but the lengths of the individual thick and thin filaments do not change.

8. Muscle relaxation ensues upon the removal of what?

Calcium ions.