What are the main functions of the skeletal system?

Five major functions Provides shape and support Enables you to move Protects your organs Produces blood cells Stores minerals and other materials

Shape and support Vertebrae – a total of 26 bones that make up your back bone Backbone is the center of your skeleton

Movement and protection Most of the body’s bones are associated with muscles Muscles pull on the bones to make them move Skull protects your brain Ribs protect lungs, heart, and digestive organs

Production and storage Tissues in the long bones of your arms and legs make certain blood cells Bones store calcium

What role do joints play? Joints allow bones to move in different ways Immoveable joints – allow little or no movement – skull Moveable joints – held together by ligaments (strong connective tissue)

Types of joints Hinge joint – allows forward and backward motion - knee Gliding joint – allows bones to slide over each other – wrist Pivot joint – allows a bone to rotate – elbow Ball and socket – greatest range of motion – shoulder and hip

What are the characteristics of bones? Compact bone – hard and dense outside layer Spongy bone – at the ends and just below compact bone

Bone Marrow Red bone marrow – fills the spaces in some of your spongy bone – makes blood cells Yellow Bone marrow – found in the space in the middle of the bone, and stores fat

Growth and health of bones Cartilage is a strong connective tissue When you were born, most of your bones were cartilage As you age, your bones start to lose minerals Osteoporosis – a condition where bones become weak and break easily