1. Muscles and Levers
Chapter 15, section 3

2. Kinds of Muscle Skeletal muscle = muscles attached to bone
Smooth muscle = involuntary muscles inside many internal organs (found in your digestive tract and walls of blood vessels)
Cardiac muscle =heart muscle, involuntary

3. Kinds of Muscle Involuntary = muscle not under your control
Example: smooth and cardiac (digestion and pumping your blood)
Voluntary = muscle you control
Example: skeletal (jumping up and down)

4. Movement
Tendons are strands of connective tissue that attach muscles to bones.
When a muscle gets shorter or contracts, the two bones it is connected to move closer.
Muscles often work in pairs to produce controlled motions.

5. Movement The muscle that bends part of your body is a flexor.
The muscle that straightens part of your body is an extensor.

6. Levers in the Body
Read Page 478 and write down a definition for the following words:
Lever
Fulcrum
Effort Force
Load
Mechanical Advantage

7. Levers in the Body Lever = rigid bar that pivots around a fixed point
Fulcrum = fixed point
Effort Force = force applied to the lever
Load = force that resists the motion of the lever
Mechanical Advantage = an increase in the amount of work that can be done with a lever.

8. Match the Body Parts Bone is the…. LEVER! Joint is the… FULCRUM!
Muscle is the…
Effort Force!
Now give an example of a lever system in your body, be sure to label what is the lever, fulcrum, etc.

9. Three Classes of Levers
The type of lever is determined by the location of the fulcrum, in relation to the load and the effort force.

10. Raising up on the balls of your feet
Class
Picture
Example
1st
Tilting the neck
2nd
Raising up on the balls of your feet
3rd
Lifting a book with your arm

11. Use it or Lose it
Exercised muscles are stronger and longer than those that are not used.
Strong muscles can also help squeeze blood to the heart.

12. Use it or Lose it
Resistance Exercise strengthens skeletal muscles by working against a weight.
Aerobic Exercise increases the muscle strength of the heart and increases endurance.

13. Muscle Injury Read page 481 and explain the terms
Strain = when a muscle or tendon is over stretched or torn.
Usually happens because of an inadequate warm-up
Tendonitis = an inflammation of the tendon that did not heal after a strain.
Anabolic Steroids = drugs that make muscles stronger and damage the heart, liver, kidneys, and can stop bone growth.