Joints

Articulation—

site where two or more bones meet

Functions of joints:

Give skeleton mobility

Hold skeleton together

Three FUNCTIONAL classifications:

immovable (synarthrosis)

slightly movable (amphiarthrosis)

• freely movable (diarthrosis)
• Three STRUCTURAL classifications:
• Fibrous (mainly immoveable)
• Cartilaginous (partially moveable)
• Synovial (freely moveable)

Joint held together with very short,interconnecting fibers, and bone edgesinterlock. Found only in the skull.

• Joint held together by a ligament.
• Fibrous tissue can vary in length, but is longer than in sutures.

• “Peg in socket” fibrous joint.
• Periodontalligament holds tooth in socket.

• Synchondroses
• Bones united by hyaline cartilage

• Symphyses
• Bones united by fibrocartilage

• All are freely moveable (diarthrotic)
• Include all limb joints; most joints of the body
• All have:
• --Joint capsule lined with synovial membrane
• --The synovial membrane produces fluid
• --Ligaments (inside and outside joint)

Bursae

--Extra fibrous sacs lined with synovial membranes, and containing synovial fluid

--Placed where ligaments, muscles, skin, tendons, or bones rub together to reduce friction at joint