The Skeletal System

5 Functions Of The Skeletal System  Support: Gives form to the body.  Protection: Protects vital internal organs, acts as a shield.  Movement: Bones and joints, bones act as levers where muscles attach in order to provide for movement.  Production: Red marrow produces blood cells.  Storage: stores mineral salts, especially calcium and phosphorus.

4 Types of Bone  Long Bone  Short Bone  Flat Bone  Irregular Bone

Types of Bone  1.)Long Bone Greater in length than in width. Absorb stress from body weight. Found in the; Arms, Forearms, Hands, Thighs, Legs, and Feet.

Anatomy of Long Bone  Long Bone Parts of Long Bone:  Diaphysis- The central shaft of the bone.  Epiphysis- Bulbous ends of the bones, shaped for muscle attachment.  Medullary Cavity- Hollow chamber that contains yellow marrow.

Anatomy of Long Bone  Long Bone Parts of Long Bone:  Endosteum- The membrane which lines the medullary cavity  Articular Cartilage- Hyaline cartilage that covers the outer surface of the epiphysis where the joints occur.

Anatomy of Long Bone  Long Bone Parts of Long Bone:  Periosteum- Dense irregular connective tissue which covers entire bone except at the joint surface. Compact Bone forms the walls of the diaphysis and thin layer around the epiphysis. Spongy Bone occupies the epiphysis and also the medullary cavity (thin layer).

Types of Bone  2.) Short Bone About equal in length and width (cubed-shaped). Found in the wrist and ankle. Spongy core enclosed in a thin layer of compact bone.

Types of Bone  3.) Flat Bone Generally thin and flat. Composed of two (more or less) parallel plates of compact bone surrounding a layer of spongy bone. Examples include: scapula, sternum, ribs.

Types of Bone  4.) Irregular Bone Complex in shape. Vary in amount of compact and spongy bone. Examples include: vertebrae, some facial bones.

Types of Bone Cells  There are three types of bone cells found in living bone. 1.Osteoblasts- (producing cells)  Found on bone surface.  Form matrix of bone in which they then become enclosed (trapped).

Types of Bone Cells 2. Osteocytes- (maintenance cells)  These are osteoblasts that are trapped inside the matrix in the lacunae chambers (mature bone). 3. Osteoclasts- (dissolving cells)  Bone cells found throughout bone tissue.  Function in bone growth and repair.