Chapter 9 Section 3

04-13-04

Muscular System: is made up of muscles and the connective tissue that attaches the muscles to the bones

3 Types of Muscles:

1) Smooth: found in the digestive tract

and the walls of blood vessels

2) Cardiac: found only in the heart

3) Skeletal: muscles that surround the

bones and protect inner organs

Types of muscle action:

1) Voluntary: under your control

2) Involuntary: not under your control

Making Connections: Tendons: connect the muscles to the bones

Working Together:

Flexor: Makes a muscle bend

Extensor: When a muscles straightens part of your body

There are more than 600 Muscles in the body.

Keeping Muscles Fit:

Aerobic Exercise: (ex. Walking, running, swimming) helps strengthen you heart and give your muscles endurance.

Resistance Exercise: (weight lifting) strengthens your skeletal muscles

Dangers of Steroids:

Anabolic Steroids: powerful drugs that resemble testosterone (male sex hormone).

Effects:

1) Threatens the heart, liver, and kidneys

2) Can cause high blood pressure

3) Can cause the bones to stop growing