Anat & Phys - Long Bone Anatomy

Epiphysis

The end part of a long bone, which is initially separated from the main bone by a layer of cartilage in growing bones. It is involved in joint formation and articulation.

Diaphysis

The shaft or long central part of a long bone that provides structural support and houses the medullary cavity.

Epiphyseal Line

The remnant of the growth plate in long bones, marking the boundary between the epiphysis and diaphysis after growth has stopped.

Articular Cartilage

A smooth, white tissue that covers the ends of bones at joints. It helps reduce friction and absorb shock during movement.

Periosteum

A dense layer of connective tissue that surrounds the outer surface of a bone, providing attachment for tendons and ligaments, and housing bone-forming cells.

Cancellous Bone (Spongy Bone)

A type of bone tissue found at the ends of long bones and in the interior of others, characterized by a porous structure filled with bone marrow, which aids in weight reduction and houses blood cells.

Red Marrow

A type of bone marrow found primarily in the spongy bone of long bones and responsible for the production of blood cells, including red blood cells, white blood cells, and platelets.

Compact Bone

A dense and sturdy type of bone tissue found beneath the periosteum, providing strength and support to the structure of long bones. It is composed of tightly packed osteons that facilitate the storage of minerals and blood supply.

Medullary Cavity

The central cavity of long bones, filled with bone marrow and surrounded by compact bone. It serves as a storage area for fat and plays a role in the production of blood cells.

Yellow Marrow

A type of bone marrow found in the medullary cavity of long bones, primarily composed of adipose tissue. It serves as an energy reserve and can convert to red marrow in times of need.

Endosteum

A thin vascular membrane that lines the inner surface of the medullary cavity and covers the trabecular bone in long bones. It plays a crucial role in bone growth, repair, and remodeling.