Test

Chapter 11

Study Guide

Learning Objectives

1.List and discuss the three generalized func¬tions of skeletal muscle tissue.

• The skeletal muscle tissue provides structural support for the entire body, surrounds soft tissue for protection, and provides the body with movement as the muscle tissue pulls on the bones when it contracts.

2. Discuss the three characteristics of skeletal muscle cells that allow them to function as they do.

• They have long fibers and contain hundreds of nuclei.

3. List and discuss the structural parts of skeletal muscle fibers that are not found in other cells.

4. Discuss the structure and function of myofila¬ments.

• Myofilaments are a basic rod-like unit of a muscle. They are composed of long proteins such as actin, myosin, and titin.

5. Explain the series of steps in muscle contrac¬tion.

1. Signal from motorneuron gets to synapse.

2. Ach is released.

3. Ach binds to receptors on motor end plate.

4. Muscle action potential sweeps into the T tubules triggering release of Ca from the cisternae of the sarcoplasmic reticulum.

5. Ca binds to troponin.

6. Troponin changes shape and shifts tropomyosin to expose binding sites of actin.

7. Myosin binds to actin.

8. Myosin head pivots.

9. Myosin releases from actin

10. Myosin re-extends into “ready” position.

6. Describe the sliding-filament theory.

• The sliding-filament theory is the theory that when muscle contracts, thick and thin filaments slide past each other and the sarcomere shortens.

7. Explain the series of steps in muscle relax¬ation.

1. Stimulation from CNS

2. Ca sequestered in SR

3. Tropomyosin shifts to cover binding side

4. Cross-bridge broken

5. No force production

8. Identify and explain the energy sources for muscle contraction.

• ATP provides the energy to pull the thin filaments together during muscle contraction.

9. Discuss aerobic and anaerobic respiration in muscle contraction.

• In the presence of...