1. The Skeletal System Skeleton composed of many different tissues: cartilage, bone tissue, epithelium, nerve, blood forming tissue, adipose, and dense connective tissue.

2. Important Functions of the Skeletal System Supporting the body Protect internal organs Attachment site for muscles making movement possible Storage of the minerals, calcium & phosphate Blood cell production occurs in red bone marrow

3. The Human Skeleton There are 206 bones in the human skeleton These bones are divided into two parts:  1) Axial skeleton- supports the central body (skull, vertebral column, and rib cage)  2) Appendicular skeleton- arms, legs, pelvis, and shoulder areas

4. The Axial Skeleton The axial skeleton supports the central axis of the body

5. The Appendicular Skeleton The bones of the arms, along with bones of the pelvis and shoulder area form the appendicular skeleton.

6. Types of Joints Immovable joint- fixed joints, with NO movement, the bones are fused together  Ex: skull Slightly movable joint- small amount of movement between two bone joints  Ex: joints between vertebrae Freely movable joint- movement in many directions

7. 4 Common Freely Movable Joints 1) Ball & Socket joint- movement in many directions

8. 4 Common Freely Movable Joints 2) Hinge joint- back and forth movement

9. 4 Common Freely Movable Joints 3) Pivot joint- allow one bone to rotate around another

10. 4 Common Freely Movable Joints 4) Saddle joint- allows one bone to slide in two directions

11. Structure of Bones Periosteum- tough membrane (connective tissue) covering bone but not cartilage Compact bone- beneath periosteum, which is dense Within Compact bone:  Haversian canal- contain blood vessels and nerves  Osteocytes- mature bone cells