1. The Muscular System
Section 1.3

2. Function Primary function is movement and flexibility
Muscles are the organs that make up the muscular system which allow you to move.
Support body by maintaining balance and posture

3. Kinds of muscle There are 3 types of muscle in the human body.
Smooth muscle- in digestive tract & blood vessels, moves food & blood
Cardiac muscle- in heart, pumps blood around body
Skeletal muscle- attached to bones, moves the body & protects organs

4. Muscle Action Voluntary- muscles under your direct control.
Skeletal muscles
Involuntary- muscles NOT under direct control (automatic).
Smooth and cardiac muscles
Occasionally skeletal muscles
Muscles move by contracting (shortening)

5. Movement Muscles pull on bones to move.
Tendons are connective tissue that attaches muscles to bones.
Muscles often work in pairs (counter each other’s movement)
Flexor- muscle that bends (flexes) a body part. Ex. biceps
Extensor- muscle that straightens (extends) a body part. Ex. triceps

6. Muscle maintenance
Muscles need to be used to maintain strength and endurance.
Exercise makes muscles stronger and larger, and therefore more efficient.
Resistance and aerobic exercise improve muscle function