gross anatomy of long bone

Gross Anatomy  of Long Bone 

Long bone consist;

1. Epiphysis

2. Metaphysis

3. Diaphysis

4. Articular cartilage

5. Periosteum

6. Medullary cavity

7. Endosteum

1. Epiphysis

These are larger rounded ends of long bone, wider than shaft as it's joint with adjacent bone.

2. Metaphysis

Narrow portion of long bone between the epiphysis and diaphysis both of the bone.

It is made up of epiphyseal (growth) plate. 

Epiphyseal plates are only places where long bone continue to grow in length after birth.

It grows and ossifies near diaphysis and epiphysis.

3. Diaphysis

Diaphysis is main or midsection (shaft) of long bone.

Hollow cylinder with walls of compact bone tissue. Center of cylinder is medullary cavity, filled with yellow bone marrow in adult.

Near the centre of diaphysis, large nutrient artery passes.

4. Articular cartilage

Smooth white tissue that covers the ends of bone where they come together to form joints.

In joint hayline cartilage is referred as articular cartilage.

Reduces friction and absorb shock.

Free movable joints.

5. Periosteum

Double layer membrane that cover outer surface of bones, except at articular surface of long bone.

Periosteum consist two layer;.

1. Outer fibrous layer

Continuing blood vessels, lymphatic vessels and nerves pass into bone.

Form bone during growth period and in fracture healing.

2. Inner fibrous layer

Contains elastic fibers, blood vessels, bone cells.

Involved in maintenance and remodeling of bone.

Function of periosteum

Essential for bone growth and repair.

Point for attachment for ligaments and tendons.

Protect bone from injury.

Provide good blood supply to bone.

Point for muscular attachment.

Contains nerves, lymphatic nerves and capillaries, provide nutrients to bone.

6. Medullary Cavity

Centre of the bone shaft (shape within diaphysis) is hollow known medullary cavity.

Contains yellow bone marrow in adults.

Cavity of cancellous bone (spongy) and medullary cavity filled with marrow.

In adult, medullary cavity filled yellow bone marrow.

Spongy bone contains red bone marrow.

Nutrient reach medullary cavity and spongy bone tissue by nutrient artery, that penetrate periosteum and compact bone.

7. Lining the medullary cavity of compact bone tissues and covering trabeculae of spongy bone tissue is endosteum.

Membrane lining the medullary cavity of bone.