1. Muscular System

2. Muscle Appearance Striated: muscles that appear banded (lines)
Smooth: Muscles that do not have bands/striations

3. Muscle Control
Voluntary: Muscles that are under your conscious control
Involuntary: Muscles that are not under your conscious control

4. Muscle Strength & Flexibility
Exercise helps muscles maintain or increase strength and flexibility
Exercise makes individual cells grow in size and number, as a result muscles become thicker and stronger.
Warm up activities increase muscles’ blood flow making them ready for exercise. Stretching decreases a muscle’s ability to contract so it should be done after exercise.

5. How Muscles Work
Muscles can only contract (pull), not extend (push), so skeletal muscles must work in pairs.
While one muscle contracts, the other in the pair relaxes allowing the joint to move.

6. Bending the Arm
Muscle shortens
Muscle relaxes

7. Straighten the Arm

8. Muscle Types
Smooth
Cardiac
Skeletal

9. Smooth
Function: Found in your internal organs and blood vessels. Involved with moving food and blood through your body
Muscle Control: Involuntary
Example:
Organs of the digestive system

10. Cardiac (Heart)
Function: Found only in the heart. Contracts over and over, pumping blood
Appearance: Striated
Muscle Control: Involuntary
Example:

11. Skeletal (Striated)
Function: Attached to your bones. Allows your body to move.
Muscle Control: Voluntary
Example: