1. The Muscular System
Functions & Anatomy

2. Functions of the Muscular System

3. Movement Movement of bones Actions of muscles Work like rubber bands
Depends on attachment points on the bones

4. Posture Maintain body position Tonic Contraction Produces no movement
Maintain muscle tone

5. Heat Production
Contraction produces heat required to maintain normal body temp.

6. Types of Muscle Tissue
Skeletal
Smooth
Cardiac

8. Skeletal Muscle Striated Voluntary “Red Meat” Attached to bones
Perform contractions that lead to movement of bones
Joints
                           

9. Smooth Muscle Non-striated (smooth) Involuntary
Found in hollow walls of organs
Intestine
Blood vessels
Etc.
Movement of materials through tubes

10. Cardiac Muscle Striated – intercalated discs Involuntary Heart
Contraction

11. Structure of Skeletal Muscle
Organs = muscles
Extend from bone to bone
Attached by tendons
Origin – fixed point
Insertion – moves during contraction

12. Microscopic Structure
Contractile fibers grouped in bundles
Contain Proteins (filaments)
Actin
Myosin
Filaments slide toward each other during contraction

14. Stimulus Muscle contracts when stimulus reaches certain intensity
All on none
Motor Unit
Nerve + Muscle
Neurotransmitter crosses gap between

15. Muscular System
Actions

16. Actions are based on…. Origin Insertion Insertions move toward origins
Fixed point of muscle attachment
Insertion
Moveable point of muscle attachment
Insertions move toward origins
Direction of muscle fibers

17. Actions Flexion (lateral*) Extension Hyperextension
Decreasing the joint angle
Extension
Increasing the joint angle
Hyperextension

18. Actions… Abduction (Hz*) Adduction (Hz*) Circumduction
Moving away from body
Adduction (Hz*)
Moving toward body
Circumduction
Cone-like movement

19. Actions… External Rotation Internal Rotation L/R Rotation lateral
Medial
L/R Rotation

20. Actions… Plantar Flexion Dorsi Flexion Inversion Eversion
Pointing toes
Dorsi Flexion
Bringing toes toward shins
Inversion
Soles sweep toward each other
Eversion
Soles sweep away

21. Actions… Pronation Supination Opposition Reposition Palms downward
Palms upward
Opposition
Thumb moves across palm
Reposition
Thumb returns

22. Actions… Depression Elevation Protraction Retraction
Lowering shoulders
Elevation
Shoulders shrug upward
Protraction
Jutting forward
Retraction
Jutting back