The Skeletal System

What the Skeletal System Does

• Your skeleton has four major functions.– Protects organs– Shape and support– Movement– Stores minerals and other materials until your

body needs them. – Produces blood cells

Shape and Support

• The backbone, or vertebral column

• is the center of the skeleton.– 26 small bones – vertebrae, make up your backbone– Is flexible and able to bend

Movement and Protection

• Most of the body’s bones are associated with muscles.– The muscles pull on the bones to make your

body move

• Bones also protect many of the organs in your body.– Touch your head, your skull protects your

brain

Production and Storage

• Storage of minerals released by the bones when your body needs it.– Like calcium and phosphorus

• Some of your bones produce substances that your body needs.– New blood cells

Types of Bone• The hard outer layer of bone is the

COMPACT BONE

• The interior region of bone that contains many tiny holes is the SPONGY BONE

Joints of the Skeleton

• A joint is a place in the body where two bones come together.

• A joint allow bones to move in different ways.

• Some joints do not move and are called immovable joints, like in your skull.

• Some joints do move and are called moveable joints.

How do joints move?

• Ligaments– Strong connective tissue– Hold bones together

• Cartilage– Connective tissue more flexible than bone– Covers the ends of bones and keeps them

from rubbing against each other.

Pivot Joint

• Located between the first two vertebrae in your neck, enabled you to shake and nod your head. It allows for rotation of one bone around another.

Hinge Joint

• The elbow and knee are hinge joints. This allows for movement in a forward and backward direction and also a little side to side.

Ball and Socket Joint

• Ball and socket joints provide for the circular motion of bones, consist of a bone with a rounded heard that fits into the cuplike pocket of another bone. Your hip and shoulder are ball and sockets.

Gliding Joint

• The gliding joint in your wrist or ankle enables you to bend and flex as well as make limited side-to-side motions.

Bone Diagram