anatomy of a long bone

Proximal Epiphysis

The knob-like end of the long bone that is closest to the trunk.

Distal Ephiphysis

The knob-like end of the long bone that is farther from the trunk.

Diaphysis

The shaft of a long bone.

Articular Cartilage

Cartilage covering bone ends at joints to reduce wear and tear.

Medullary Cavity

The hollow space inside the diaphysis that contains yellow marrow.

Yellow Marrow

Stores fat.

Spongy Bone

Bone tissue with spaces, found inside epiphyses and filled with red marrow.

Compact Bone

Dense bone with no spaces; makes up the outer layer of the diaphysis.

Red Marrow

Found in spongy bone; contains stem cells that produce blood cells.

Endosteum

A connective tissue membrane lining the medullary cavity (“inside-bone”).

Periosteum

A vascular, innervated connective tissue membrane covering the outside of the bone (“around-bone”).

Nutrient Foreamen

A small hole that allows blood vessels to enter and exit the bone.

Epiphyseal Plate

The growth plate made of hyaline cartilage that ossifies and regrows, causing height growth.

Examples

The femur, humerus, radius, ulna, tibia, and fibula.