1. The Muscular System
Support Systems
Unit 2

2. Functions of the Muscular System
Heat Production (thermogenesis)
Heat is a byproduct of muscle contraction
Movement Facilitation
Muscles shorten and pull on bones which produces movement
Structure (postural support)
Contraction of muscles keeps us upright and maintains posture

3. Functions cont. Protection of Internal Organs
Contraction of abdominal muscles causes them to become hard and offers protection to the underlying organs
Other muscles con contract prior to receiving a blow thus protection bones and soft tissue.
Controls the volume of hollow organs
Smooth muscle surrounds our hollow organs and contractions propel the substances through them, aid in their emptying, or helps control their volume
Stomach and small intestines
The bladder
Blood vessels

4. Anterior Skeletal Muscles

5. Posterior Skeletal Muscles

7. Cardiac Muscle Striated – appears striped under a microscope
Involuntary- no conscious control
Found in the heart

8. Smooth Muscle Located in walls of hollow internal surfaces such as:
blood vessels - stomach
urinary bladder - intestines
Non-striated in appearance
Involuntary

9. Skeletal Muscle Attached to bones
Striated appearance under a microscope
Voluntary control (conscious control)

10. Diseases and Disorders of the Muscular System

11. Tendonitis
Characterized by Inflammation of the tendons due to overuse or age-related changes of the tendon.
Common in individuals who begin a new exercise or increase their level of exercise.
Treatment includes: rest, ice, compression, and elevation (RICE).

12. Strains A tearing of a muscle or its attaching tendon
Occurs when a muscle receives a stress that overcomes its strength
Sudden, quick heavy lifting
During sports
While performing work tasks

13. Strains cont. 3 types of strains
A 1st degree occurs when the muscle is stretched causing micro-tears in the muscle fibers
A 2nd degree strain occurs when the muscle or tendon is partially torn
A 3rd degree strain occurs when the muscle is completely ruptured
Signs & symptoms include:
Pain, especially when the muscle is contracting which limits function
Swelling
Bruising
Treatment includes Rest, Ice, Compression, Elevation

14. Muscle Spasm An involuntary muscle contraction
Also called a “Charlie Horse” or “muscle cramp”
Main causes are electrolyte imbalances, dehydration and fatigue

15. Muscle Spasm cont.
Initial treatment is to put the muscle that has the spasm on stretch
If spasm persists ice or heat can be used
Prevention incudes maintaining a proper diet, drinking plenty of water and proper conditioning
Sports drinks may be beneficial during exercise to help replace lost sodium due to sweating

16. Muscular Dystrophy
An inherited disorder in which the muscles are missing a certain protein causing degeneration of muscle tissue
Causes progressive weakness and loss of function of the affected muscles
There is no cure but physical therapy can lessen the severity of the disorder.