1. The Skeletal System 5 major functions- It provides shape and support. Enables you to move. Protects your internal organs. Produces blood cells. Stores certain materials until your body needs them.

2. Bones, strong and living Bone strength- strong and light weight, can absorb more force than concrete or granite. Bone growth- as an infant the bones consist of cartilage, As you grow the cartilage turns to bone. Cartilage- connective tissue that is more flexible than bone.

3. Structure of bone Bone marrow- soft connective tissue which produces red and white blood cells. Compact bone- hard and dense but not solid. Spongy bone- at the end of the bone its light weight but strong with small spaces between it. Outer membrane- covering of the bone except at the end of the bone. Canal- carries the blood vessels. Blood vessels- carry blood.

4. Joints of the skeleton 2 types Immovable- the least flexible joint with little or no movement. Movable- joints that move.

5. Joints Ball and socket- allows the greatest range of motion. Example: in your shoulder. Pivot- allows one bone to rotate around another. Example: your neck. Hinge- allows extensive forward or backwards motion. Example: your knee or elbow. Gliding- allows one bone to slide over another. Example: wrist and ankles. Ligament- connective tissue that hold the bones together.

6. Bone and joint injuries. 3 types. Fracture- break in the bone. Sprain- occurs when ligaments are stretched to far and tear in places. Dislocation- occurs when a bone comes out of a joint. X-ray- form of energy that travels through soft tissue but not bone. MRI- burst of magnetic energy that causes the atoms to vibrate create an image. Osteoporosis- A condition in which the body’s bones become weak and break easily.

7. Muscle Action 2 types: Involuntary- Muscles not under your conscious control.(Example- heart) Voluntary- Muscles that you control.

8. Muscle types: Skeletal muscles- Attached to the bones of your skeletons. Provides the force that moves your bones. Voluntary and striated. Smooth muscles- Are involuntary muscles That controls many types of movements inside your body. Not striated. Cardiac muscle- Involuntary muscles that has characteristics in common with both smooth and skeletal muscles. Striated.

9. Muscles at work Muscles can only contract. When one contracts the other goes to its original length. Muscles have to work in pairs.

10. The Skin Functions of the skin: the skin covers the body and prevents the loss of water Protects the body from injuries and infections. Skin helps to regulate the body temperature. eliminates wastes, gathers information about the environment and produces vitamin D.

11. The Epidermis Outer most layer of the skin. Doesn’t have nerves or blood vessels. It is made up of dead skin cells. Thinner then the Dermis. Contains melanin. Melanin – a pigment, or color substance that gives skins its color. Pores are on the Epidermis.

12. The Dermis Lower layer of skin. Contains nerves and blood vessels. Contain sweat glands, oil glands, and hair follicles.

13. WE ARE DONE