Structure of a Long Bone

These flashcards cover key terms and concepts related to the structure of long bones, including their composition, types of bone cells, and various types of bone.

Diaphysis

The shaft of a long bone.

Epiphysis

The ends of a long bone.

Metaphysis

The expanded ends of the diaphysis that join the epiphysis.

Epiphyseal growth plate

A plate of cartilage that joins the diaphysis and epiphysis in a growing bone.

Medullary cavity

The central space within the shaft of a long bone.

Compact bone

Also known as dense bone; thickest in the diaphysis and provides strength.

Cancellous bone

Also known as spongy bone; consists of rods and plates forming trabeculae.

Trabeculae

The rods and plates that make up the structure of cancellous bone.

Yellow bone marrow

The type of bone marrow that is mostly fat; prevalent in the diaphysis of adult long bones.

Red bone marrow

Hematopoietic bone marrow responsible for the synthesis of blood cells.

Osteoblasts

Active cells that synthesize matrix components of bone.

Osteocytes

Mature bone cells that maintain the bone matrix.

Osteoclasts

Multi-nucleated giant cells responsible for bone resorption.

Type I collagen

The abundant protein fiber in bone tissue synthesized by osteoblasts.

Periosteum

A layer of dense connective tissue that covers the outer surface of bones.

Endosteum

A thin connective tissue lining the medullary cavity of a bone.

Haversian canals

Central canals in compact bone that contain blood vessels and nerves.

Osteon

The structural unit of compact bone, consisting of a central Haversian canal surrounded by concentric layers of matrix.

Volkmann's canals

Transverse canals that connect Haversian canals and contain blood vessels and nerves.

Lacunae

Small spaces in bone tissue that house osteocytes.

Interstitial lamellae

Remnants of older osteons that remain between the current osteons.

Lamellar bone

Mature bone that is organized into regular layers.