1. THE MUSCULAR SYSTEM
Chapters 10 & 11

2. Objectives
Describe the arrangement of fascicles in the various types of muscles.
Identify different muscles in the axial and appendicular skeletons.
Describe what happens during aging in the muscular system.

3. Muscle Organization and Function
Muscles are made of muscle fibers
Fibers are bundled into fascicles
Fascicle organization classifies muscle type

4. Parallel Muscle Most skeletal muscles
Many have a central body in the middle
Ex:
Biceps brachii

5. Convergent Muscle
Broad muscles that attach at a common attachment site
Ex:
Pectoralis muscles

6. Pennate Muscle Fascicles form an angle with the tendon Ex:
Extensor digitorum
Rectus femoris
Deltoid

7. Circular Muscle Sphinchters Concentrically arranged around an opening
Ex:
Orbicularis oris

9. Muscle Terminology
Muscles can be identified by their origin, insertion, and action
Origin
Where the fixed end of a muscle attaches to bone, cartilage, or connective tissue
Insertion
Where the movable end attaches to another structure
Action
Movement from muscle contraction

10. The Axial Muscles On the axial skeleton Functions: 60% of muscles
Position head and spinal column
Move the rib cage
Make breathing possible
60% of muscles

11. The Appendicular Muscles
Move the skeleton
40% of muscles

12. Aging and the Muscular System
Skeletal muscle fibers:
Become smaller
Lose elasticity
Lose tolerance for exercise
Higher recovery time from injury

14. Cardiac Muscle Contracts ~70 times/minute Pumps ~5 liters blood/minute
Intercalated disc
connects muscle fibers; allows transport of ions between cells
Nuclei

15. Smooth Muscle
Found in the walls of all the hollow organs of the body (except the heart)
Regulates flow of blood through the arteries
Moves food through GI tract
Expels urine
Pushes babies out
Regulates flow of air through the lungs
Involuntary

16. Skeletal Muscle
Muscles attached to the skeleton
Voluntary
Striated