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.