• The word skeleton is derived from a Greek word that means “dried-up body”.

oLegs, pelvis, vertebrae (spine) hold the body UP

oSupport muscle and other tissue types

• Jaw (mandible & maxilla) serve to support teeth

o Encloses and protects vital organs

• Ex. Brain enclosed by skull; rib cage protects the heart, lungs, and other organ of the thorax.

Bone act as lever when attached muscles contract, causing movement about joints.

oMinerals (calcium, phosphorous) – within the matrix of bone tissueoEnergy reserve (adipose) – within the yellow marrow of long bones

or blood cell formation

oRed bone marrow of an adult produces white and red blood cells and platelets.

Long bones

Short bones

Flat bones

Irregular bones

Sesamoidbones

Sutural bones

Bones are classified by their basic shape

–LONG BONE

• A bone whose length is greater than its width.

• Act as levers that are pulled by contracting muscles.

• e.g., humerus, femur

–FLAT BONE

• Are actually thin or curved more often then they are flat.

–FLAT BONE

• main function is to provide protection to the bodies vital organs and being a base for muscular attachment

• e.g ribs, scapulae, sternum, skull

–SUTURAL BONE

–IRREGULAR BONES

• They do not fit neatly into

any other category, due to their non-uniform shape

• e.g. vertebrae, many facial bones, hipbone

–SHORT BONES

• Are about equal in length, width, and thickness, but they are shaped

irregularly

• e.g., carpals,

tarsals, patella

–SESAMOID BONES

• Are small bones embedded within certain tendons.

• Helps the tendon overcome compression

forces, increasing

the mechanical

efficiency of joints.

The shaft of a long bone

A hollow cylinder with walls of compact bone tissue.

DIAPHYSIS

(compact bone)

Ends of the long bone and

articulates or meets with a second bone at a joint

consist mainly of spongy bone

surrounded by a thin layer of compact bone

EPIPHYSIS

(spongy bone)

EPIPHYSIS

pad of hyaline cartilage on the epiphyses where long bones articulate or join."shock absorber“ -It forms a smooth, shiny surface that decreases friction within a joint.

ARTICULAR

CARTILAGE

ARTICULAR

CARTILAGE

remnant of epiphysealdisk/plate.cartilage at the junction of the diaphysis and epiphyses (growth plate).

is the wider portion of a long bone adjacent to the epiphysealplate.part of the bone that grows during childhood; as it grows, it

ossifies near the diaphysis and the epiphyses.

•In the adult- filled with yellow bone marrow and functions as a storage site for fat.

inside this cavity is lined with connective tissue called the

endosteum.

MEDULLAR

CAVITY

ENDOSTEUM

inner lining of medullarycavity.contains layer of osteoblasts & osteoclasts.

Double layered membrane surrounding bone except at articular cartilage.Inner cellular layer contains osteoprogenitor cells, osteoblasts,

osteoclasts; therefore functions in bone growth & repair.

Outer fibrous layer of dense irregular CT for attachment of tendons& ligaments; provides route for blood vessels & nerves; separates bone tissue

from surrounding tissues.

PERIOSTEUM

Distal

epiphysis

Proximal

epiphysis

diaphysis

yellow marrow

periosteum

compact bone

spongy bone

Endosteum

hyaline cartilage

Sharpey’s fibers

epiphyseal line

THANK YOU!