Section 4.1 Classifications of Joints

Practice flashcards covering the structural and functional classifications of joints, their mobility levels, movement types, and specific anatomical examples.

Joint (articulation)

Where adjacent bones, or bone and cartilage, come together.

Structural Classification

Classification based on how bones are connected and if a joint cavity exists.

Fibrous Joints

Joints united directly by fibrous connective tissue (collagen fibers) with no joint cavity.

Suture

A fibrous joint with short fibers that is immobile (synarthrosis), such as skull bones.

Syndesmosis

A fibrous joint with longer fibers that ranges from immobile to slightly mobile.

Gomphosis

A fibrous joint involving the periodontal ligament that is immobile, such as the teeth.

Cartilaginous Joints

Joints united by hyaline cartilage or fibrocartilage with no joint cavity.

Synchondrosis

A cartilaginous joint united by hyaline cartilage that is immobile.

Symphysis

A cartilaginous joint united by a thick pad of fibrocartilage that is slightly moveable (amphiarthrosis), such as intervertebral discs.

Synovial Joints

Joints where articulating surfaces touch within a fluid-filled joint cavity and are all freely moveable (diarthrosis).

Functional Classification

Classification based on the amount of mobility; more stability/protection equals less movement.

Synarthrosis

An immobile joint providing a strong union to protect internal organs, such as sutures or the manubriosternal joint.

Amphiarthrosis

A slightly moveable joint providing limited mobility and high structural stability, such as the pubic symphysis.

Diarthrosis

A freely moveable joint providing extensive movement, mostly found in the appendicular skeleton.

Uniaxial (Monaxial)

A category of diarthrosis moving in one plane/axis, such as the elbow.

Biaxial

A category of diarthrosis moving in two planes/axes, such as the metacarpophalangeal/knuckle joint.

Multiaxial (Triaxial)

A category of diarthrosis moving in three axes (anterior-posterior, medial-lateral, and rotation), such as the shoulder or hip.

Linear (Gliding) Movement

Movement where a joint slides, comparable to a pencil held upright with an unsecured point sliding.

Angular Movement

Movement where the joint point is held still and the shaft moves.

Circumduction

Movement where the joint point is held still and the shaft moves in a circle.

Rotation

Movement where the joint point is held still and the shaft twists vertically around its long axis.