The Skeletal System

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

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

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

The Axial Skeleton

The axial skeleton supports the central axis of the body

The Appendicular Skeleton The bones of the arms,

along with bones of the

pelvis and shoulder area

form the appendicular

skeleton.

Types of Joints

Immovable joint- fixed joints, with NO movement, the bones are fused togetherEx: skull

Slightly movable joint- small amount of movement between two bone jointsEx: joints between vertebrae

Freely movable joint- movement in many directions

4 Common Freely Movable Joints

1) Ball & Socket joint- movement in many directions

4 Common Freely Movable Joints

2) Hinge joint- back and forth movement

4 Common Freely Movable Joints

3) Pivot joint- allow one bone to rotate around another

4 Common Freely Movable Joints

4) Saddle joint- allows one bone to slide in two directions

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

nervesOsteocytes- mature bone cells