1. 1
C H A P T E R
Muscle Physiology

2. Chapter Outline Skeletal muscle macrostructure and microstructure
Sliding-filament theory of muscular contraction
Fiber types
Types of muscle action
Force production

3. Three Types of Connective Tissue: Epimysium, Perimysium, and Endomysium

4. A Motor Unit

5. Sectional View of a Muscle Fiber

6. Detailed View of Myosin and Actin Protein Filaments in Muscle

7. 
The discharge of an action potential from a motor nerve signals the release of calcium from the sarcoplasmic reticulum into the myofibril, causing tension development in muscle.

8. Contraction of a Myofibril: Stretched Muscle

9. Contraction of a Myofibril: Partially Contracted Muscle

10. Contraction of a Myofibril: Completely Contracted Muscle

11. 
Calcium and ATP are necessary for myosin cross-bridge cycling with actin filaments.

12. 
Type II, or fast-twitch, muscle fibers are capable of developing higher forces than Type I, or slow-twitch, muscle fibers— especially at higher velocities of muscle action.

13. 
The number of cross-bridges that are attached to actin filaments at any instant in time dictates the force production of a muscle.

14. Force-Velocity Curve for Eccentric and Concentric Actions

15. Three Arrangements of Muscle Fibers
Fibers parallel to tendon
Unipennate muscle
Bipennate muscle

16. 
Many factors may affect rate of cross-bridge cycling and thus force, including neural activation, calcium concentration, myosin ATPase activity, preloading, prestretch, muscle fiber type and ultrastructure, fatigue through a variety of mechanisms, and number of contractile components (myosin and actin) in parallel.