Chapter 6 - Skeletal System Vocabulary

Amphiarthrosis

A slightly movable joint, such as the joint between the vertebrae.

Appendicular skeleton

The part of the skeleton that includes the limbs and the girdles (shoulder and pelvic) that attach them to the axial skeleton.

Articulation

Another word for a joint; it’s where two or more bones meet.

Axial skeleton 

The part of the skeleton that forms the central axis of the body, including the skull, vertebral column, and rib cage.

Bursa

A small fluid-filled sac that reduces friction between bones, tendons, and muscles near joints

Compact bone

Dense, hard bone tissue that forms the outer layer of bones; it provides strength and protection.

Diaphysis

The long, central shaft of a long bone.

Diarthrosis 

A freely movable joint, like the shoulder, knee, or elbow.

Epiphysis

The enlarged ends of a long bone, where it connects to other bones at joints.

Fracture

A break or crack in a bone.

Ligament

A tough band of connective tissue that connects bone to bone, providing joint stability.

Marrow cavity (Medullary cavity) 

The hollow space inside the diaphysis of a long bone that contains bone marrow.

Meniscus

A curved piece of cartilage in joints (like the knee) that cushions and stabilizes movement.

Ossification

The process of bone formation from cartilage or other tissues.

Osteoclast 

A bone cell that breaks down and removes old or damaged bone tissue.

Osteocyte

A mature bone cell that maintains the bone matrix and communicates with other bone cells.

Osteon (Haversian system)

The structural unit of compact bone, consisting of concentric rings (lamellae) around a central canal.

Periosteum

A tough, fibrous membrane that covers the outer surface of bones and contains blood vessels and nerves.

Spongy bone (Cancellous bone) 

Lightweight, porous bone tissue found inside bones, especially at the ends; it contains red bone marrow.

Synarthrosis

An immovable joint, such as those between the bones of the skull.

Synovial fluid

The slippery fluid inside joint cavities that reduces friction and nourishes cartilage.