Anatomy of a Long Bone

Periosteum

Covers and protects blood vessels, nerves, and osteoblasts in the bone.

Endosteum

Lines the medullary cavity.

Compact bone

Hard outer layer of the bone.

Diaphysis

The main section of a long bone. / Long shaft of the bone.

Epiphysis

The 2 ends of the bone shaft.

Spongy bone / Red marrow

Found in the heads of long bones. Produces red blood cells.

Endosteum

A membrane that lines the medullary cavity and keeps yellow marrow intact.

Yellow marrow

Fat storage in the medullary cavity

Hematopoiosis

Production of blood cells

Erythropoiesis

Production of red blood cells

Leukopoiesis

Production of white blood cells

Erythropoietin

Hormone the kidney produces for bones

Thyroid

Releases hormone for osteoblasts

Parathyroid

Releases hormone for osteoclasts

Decreased bone mass

Bone mass peaks : Decreased physical activities / metabolic activity : Fractures, and bone breaking / change in bone shape.