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 BoneShort Bone Flat BoneIrregular Bone

Types of Bone

1.)Long BoneGreater in length than in width.Absorb stress from body weight.Found in the; Arms, Forearms,

Hands, Thighs, Legs, and Feet.

Anatomy of Long BoneLong 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 BoneLong 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 BoneAbout 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 Bone3.) 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 BoneComplex in shape.Vary in amount of compact and

spongy bone.Examples include: vertebrae,

some facial bones.

Types of Bone CellsThere 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.