chapter 9: joints-synovial joints

Articular cartilage

layer of hyaline cartilage that covers the facing surfaces of two bones

Joint (articular) cavity

separates articular surfaces

Synovial fluid

slippery lubricant in joint cavity

Joint (articular) capsule

connective tissue that encloses the cavity and retains the fluid

• ball-and-socket joint

• pivot joint

• saddle joint

• hinge joint

• plane joint

• condylar joint

what are the 6 types of synovial joints

Synovial joints: ball-and-socket joints

• Smooth, hemispherical head fits within cup-like socket

• Only multiaxial joints in body

• Examples: shoulder, hip

Synovial joints: Condylar joints

• Oval convex surface of one bone fits into a complementary-shaped depression on the other

• Biaxial joints—movement in two planes

• Examples: radiocarpal joint, metacarpophalangeal joints

synovial joints: saddle joints

• Both bones have an articular surface that is shaped like a saddle, one concave, the other convex

• Biaxial joints

• Examples: trapeziometacarpal (opposable thumb), sternoclavicular joint

Synovial joints: Plane (gliding) joints

• Flat articular surfaces, bones slide over each other

• Usually biaxial joints

• Examples: between carpal bones of wrist; between tarsal bones of ankle; also between articular processes of vertebrae

synovial joints: hinge joints

• One bone with convex surface fits into a concave depression of another bone

• Monoaxial joints—move freely in one plane

• Examples: elbow, knee, joints within fingers, toes

synovial joints: pivot joints

• A bone spins on its longitudinal axis

• Monoaxial joints

• Examples: atlantoaxial joint (C1 and C2), radioulnar joint at the elbow

Zero position

the position of a joint when a person is in the standard anatomical position

types of movement at synovial joints: adduction and abduction

types of movement at synovial joints: circumduction

types of movement at synovial joints: rotation, lateral rotation, and medial rotation

types of movement at synovial joints: elevation, depression 

types of movement at synovial joints: protraction, retraction

types of movement at synovial joints: inversion, eversion

types of movement at synovial joints: dorsiflexion, plantar flexion

types of movement at synovial joints: supination, pronation

types of movement at synovial joints: opposition