6.2 Long Bone Anatomy

Diaphysis

Shaft, or middle section, of a long bone

Epiphysis

The enlarged end of the bone.

Articular cartilage

Thin layer of hyaline cartilage located on the distal and proximal epiphysis of the bone.

Periosteum

Tough layer of fibrous connective tissue that surrounds the bone and is continuous with tendons and ligaments

Medullary Cavity

Hollow space within the diaphysis which contains bone marrow

Endosteum

Thin layer of connective tissue cells lining the medullary cavity and the trabeculae of spongy bone inside the bone

Red marrow

Located within the spongy bone and is the site of blood cell formation (hematopoiesis)

Yellow marrow

Located in the medullary cavity of the adults and functions as a fat storage area

Compact bone

Layer of protective hard tissue that is composed of repeating units of osteons and is the outer portion of the bone

Spongy bone

Mesh-like tissue made of interconnecting trabeculae and spaces filled with red marrow and is the inner part of the bone

Epiphyseal plate

A band of hyaline cartilage found between the diaphysis and epiphyses of long bones during childhood and adolescence and turns into line once bone is no longer growing; area where bone increases in length