Purpose of the Muscular System

1. Purpose of the Muscular System Maintains Posture: supports the body in an upright position Movement: muscles attach to bones to pull them, moving substances within body (food through intestines, blood in veins) Balance: stabilizes body position Body Temperature: produces heat through muscle contraction

2. Types of Muscles Involuntary Muscle- not under your control Smooth Muscle- found in the digestive tract and the walls of blood vessels Cardiac Muscle- found only in your heart; never gets tired Voluntary Muscle- muscles you can control Skeletal Muscle attached to your bones for movement

3. Movement Tendons: thick bands of tissue that connect muscle to bone How Muscles Work Work in pairs, while one muscle contracts or bends (flexor), the other muscle relaxes or straightens (extensor) example: biceps and the triceps muscles - Always pull, never push - Only work in one direction

4. Medical Problems Strain: “pulled muscle,” overstretching or tearing of a muscle Fatigue: “tired muscle; ” cannot generate as much force Tendinitis: occurs at the site where the tendon attaches to the bone and the area becomes hot or inflamed