1. Muscular System X

2. The Muscular System Main function of a muscle:
Contraction (shortening)
Because muscles can contract:
The main functions of the muscular system are:
Movement
Maintains Posture
Stabilizes Joints
Generates Heat
Controls Openings (sphincters)
Expressions
Protection (reflexes)

3. Three basic muscle types are found in the body
Skeletal muscle
Cardiac muscle
Smooth muscle can you distinguish which is which?

4. Characteristics of Muscles
Skeletal and smooth muscle cells are elongated
***(a muscle cell is also referred to as a muscle fiber)
Some skeletal muscle cells can be up to a foot long in length
All muscles share some terminology
If you see myo- mys- or sarc- you think MUSCLE!
Prefixes myo and mys refer to “muscle”
Prefix sarco refers to “flesh”

5. Comparison of Skeletal, Cardiac, and Smooth Muscles
Table 6.1 (1 of 2)

6. Comparison of Skeletal, Cardiac, and Smooth Muscles
Table 6.1 (2 of 2)

7. Terminology Review Endo- Inside, Within (endoskeleton)
Peri- Around, surround (perimeter)
Epi- On, over, above (epidermis)

8. Our Focus: SKELETAL MUSCLE (Striated)

9. Skeletal Muscle Characteristics
Attached to the skeleton
Attached by tendons to bones (or aponeuroses)
Cells are multinucleate (many nuclei)
Striated (have visible banding)
Strong force
Tire easily (muscle fatigue)
Voluntary—you control them (exception = reflexes)

10. Connective Tissue Wrappings of Skeletal Muscle
Cells are surrounded and bundled by connective tissue
Endomysium—encloses a single muscle fiber
Perimysium—wraps around a group of muscle fibers forming a fascicle (bundle of muscle fibers)
Epimysium—covers the entire skeletal muscle (many fascicles)

11. Connective Tissue Wrappings of Skeletal Muscle
Figure 6.1

12. Let’s build a model of a muscle.