1. MUSCULAR SYSTEM

3. Functions of the Muscular System
Without muscles, nothing in your body would work
All body movements depend on muscles
Pump blood throughout your body
Move food through your digestive system
Control the movement of air in and out of your lungs

4. Muscle Facts There are over 600 muscles in the body
40% of your total weight is muscles
Eyelids are the busiest muscles in the body
The gluteus maximus is the largest muscle in the body
There are 30 facial muscles

5. How Muscles Work
Muscles work by means of two complementary-or opposing- actions
These are contraction, the shortening of a muscle, and extension, the stretching of a muscle
Muscle contraction is triggered by nerve impulses
Muscles are only able to contract or pull
Lactic acid is a waste produced when muscles contract

6. Structure of the Muscular System
The basic unit of a muscle is muscle cell
A muscle is composed of bundles of fibers and cells
The major muscles in the body are made up of hundreds of bundles
A muscle fiber is made up of even smaller units called myofibrils
Each myofibril is in turn made up of microscopic filaments called actin and myosin, proteins that control muscle contraction.
The two types of muscle fibers are slow and fast

7. Types of Muscles Your body has three basic types of muscle tissue:
Smooth muscle
Skeletal muscle
Cardiac Muscle

8. Smooth Muscles
Are the type of muscle concerned with the movements of internal organs
Found in the intestines, the bronchi of the lungs, the stomach, the bladder, and the walls of the blood vessels
Also called involuntary muscles because they work without a person’s conscious control

9. Skeletal Muscles
Are the striped, or striated, muscles attached to bones that cause body movements
Form the largest part of the body’s muscular system
More than 600 such muscles
Are voluntary, under conscious control
Two or more skeletal muscles may oppose each other’s actions
While one contracts, the other relaxes
Classified according to the type of action each muscle performs
Muscles that close a joint are called flexors
Muscles that open out a joint are called extensors

10. Cardiac Muscles
A special type of striated tissue that forms the walls of the heart
Your heart is the most important muscle in your body
Its unique properties enable it to contract rhythmically about 100,000 times a day to pump blood throughout the body
Involuntary muscle

11. Major Muscles
Deltoids are the muscles in each shoulder, which help you move your shoulders every which way
Pectoralis are found on each side of your upper chest
Abdominals
Triceps are the large, three headed muscles that form the back of the upper arm
Biceps

12. Injury Related Muscular problems
Muscle strain- a strain, or a “pulled muscle,” is a tearing or stretching of muscle fibers as a result of suddenly pulling them too far
Muscle cramp is a sudden muscle contraction causing severe pain
Bruise is a discolored area under the skin caused by leakage of blood after an injury
Tendinitis is the inflammation of a tendon, usually caused by overuse.
Achilles is the strongest tendon in the body