1. Movement in the Human Body

2. Your muscular system, skeletal system and nervous system work together to move your body.

3. Skeletal System & Joints
Joint: A place where two or more bones meet.

4. Skeletal System & Joints
Immovable (fixed) joints: allow little or no movement, example: joints in the skull and pelvis

5. Skeletal System & Joints
Movable joints: allow the body to make a wide range of movements.
Ligaments connect bone to bone at joints.

6. TYPES OF MOVABLE JOINTS
Ball-and-socket joint.
Examples: hip and shoulder; allows greatest range of movement

7. TYPES OF MOVABLE JOINTS
Pivot joint. Examples: turning of the head or turning of the lower arm

8. TYPES OF MOVABLE JOINTS
Hinge joint. Examples: knees & elbows; in fingers & toes

9. TYPES OF MOVABLE JOINTS
Sliding joint. Examples: wrists, ankles and vertebrae

10. Muscular System Muscles work in pairs to move the body.

11. Muscular System
Ex: To bend the arm at the elbow, the biceps muscle contracts and the triceps muscle relaxes.

12. Muscular System
To straighten the arm, the triceps muscle now contracts and the biceps muscle relaxes.

13. Muscular System
Muscles are attached to bones by thick bands of tissue called tendons.
tendon
If you tear a tendon, your muscle will not be attached to the bone correctly and you will have trouble moving the bone/body part.

15. A machine with only one movement
Provide mechanical advantage

16. What is mechanical advantage?
Mechanical advantage is a measure of how much help a machine is going to be when you do work.
Mechanical advantage compares the force you exert (effort or input force) to the force you must overcome (resistance or output force).

17. Types of Simple Machines

18. click here for levers video clip.mov
A lever is a rigid object that pivots about a point (the fulcrum)
With a lever you can gain mechanical advantage and lift heavy weights easily.
click here for levers video clip.mov

19. There are three classes of levers.
Draw & label each class of levers

20. Examples of First Class Levers

21. Second Class Lever

22. Examples of Second Class Levers

23. Third Class Lever

24. Examples of Third Class Levers

25. Levers in Your Body
Your skeletal system and muscular system work together to move your body like machine parts work together to move things.
Bones function as levers and muscles supply the force to move your bones.

26. HOW IT WORKS connect muscles to bones
Bones, joints, muscles, and tendons form lever systems.
Bone:
Joint:
Muscle:
Tendons:
Rod/plank of lever
Fulcrum
Supplies input force
connect muscles to bones

27. Simple Machines in Your Body
First Class Lever-
Head moving up and down: The joint at the top of the neck is the fulcrum. Neck muscles provide the effort force to move your head up and down.

28. Simple Machines in Your Body
Second Class Lever-
Raising the body up on your toes: Ball of your foot is the fulcrum. Calf muscles provide the effort force to raise the body.

29. Simple Machines in Your Body
Third Class Lever-
Bending arm: The biceps muscle contracts to provide the effort force to lift your lower arm at the elbow or fulcrum.