1. describe the gross and microscopic structure of skeletal muscles.

2. describe the nature of a muscle twitch and explain how summation and tetanus are produced.

3. distinguish between isometric and isotonic contractions.

4. explain how the series-elastic components affects muscle contraction.

5. define the term motor unit and explain how motor units are used to control muscle contraction.

6. describe the structure of myofibrils and explain how it accounts for the striated appearance of skeletal muscle fibers.

7. explain what is meant by the sliding filament theory of contraction.

8. list the events that occur during cross-bridge cycles and describe the role of ATP in muscle contraction.

9. explain how tropomyosin and troponin control muscle contraction and relaxation, and describe the role of Ca²⁺ and the sarcoplasmic reticulum in excitation-contraction coupling.

10. describe the structure and function of muscle spindles and explain the mechanisms involved in a stretch reflex.

11. explain the function of Golgi tendon organs and explain why a slow, gradual muscle stretch could avoid the spasm that may result from a rapid stretch.

12. explain what is meant by reciprocal innervation and describe the neural pathways involved in a crossed-extensor reflex.

13. explain the significance of gamma motoneurons in the neural control of muscle contraction and in the maintenance of muscle tone.

14. describe the neural pathways involved in the pyramidal and extrapyramidal systems.

15. explain the significance of the maximal oxygen uptake, and the function of phosphocreatine in muscles.

16. explain how slow-twitch, fast-twitch, and intermediate fibers differ in structure and function.

17. describe skeletal muscle metabolism during exercise, and explain how muscles fatigue and how muscle fibers change as a result of physical training.

18. compare cardiac muscle and skeletal muscle in terms of structure and physiology.

19. describe the structure of smooth muscle, and explain how its contraction is regulated.