The Skeletal System

Warm Up: What would your body be like if you did not have a skeleton? Write a paragraph 5 or more lines

5 Major Functions of the Skeleton Provides shape and support Enables you to move Protects your internal organs Produces blood cells Stores minerals and other materials until your body needs them.

Shape and Support The backbone or vertebral column is the center of the skeleton. There are 26 bones or vertebrae that make up your backbone. Bend forward at your waist and feel your own vertebral column. If it were just one bone you would not be able to bend or twist.

Enables you to move Most of the bones in your body are associated with muscles. The two together are what enables you to move. Muscles pull on the bones to make the body move.

Protects your organs Your skull protects your brain. Your breastbone and ribs form a protective cage around your heart and lungs.

Produces blood cells The long bones of your arms and legs are factories that produce blood cells.

Stores materials The bones store calcium and phospherus. When the body needs these minerals the bones release small amounts of them into the blood.

Joints of the Skeleton Joint Where two bones come together. Allow bones to move in different ways.

Two kinds of joints Immovable Joints Moveable Joints Some joints connect bones that allow no movement. The bones of the skull are an example of an immoveable joint. Moveable Joints Most of the joints in the body are moveable joints. Held together by a strong connective tissue called ligaments.

Moveable Joints Goto phschool.com cep-4012 Hinge Joint: allows forward and backward motion. Knee and elbow Ball-and-Socket Joint: allow you to swing freely in a circle. Shoulder and hip Pivot Joint: allows one bone to rotate around another. Neck Gliding Joint: allows one bone to slide over another. Wrist and ankle

Now you try! Name that joint. Move your arm in a circle. Ball-and-Socket Joint Move head from side to side Pivot Joint Squat down Hinge, Ball-and-Socket, & Gliding Joint Push open a door Hinge, Ball-and-socket, & Gliding Joint

Bone Structure Show overhead of bone Outer membrane: Thin tough covering (except the ends) Where blood vessels and nerves enter and leave the bone. Compact bone: Under outer membrane. Hard and dense, but not solid. Canals that carry blood vessels and nerves from the surface to the living cells in the bone. Spongy bone: Many small spaces like a sponge; make the bone strong and lightweight. Marrow: fills the spaces with soft connective tissue. Red bone marrow: produces most of the bodies blood cells. Yellow bone marrow: Store fat

What is true about how a bone forms? As the body grows, the cartilage in the skeleton is replaced with hard bone tissue. Cartilage covers the ends of many bones in the body of an adult.

The truth about bones Lightweight Hard because they contain minerals.

When do bone cells form new tissue? During growth In response to the force of the weight of our bodies To heal broken bones