JOINTS

• FUNCTIONAL CLASSIFICATION– Synarthroses: immovable– Amphiarthroses: slightly movable– Diarthroses: freely movable

• STRUCTURAL CLASSIFICATION– Fibrous joints: bones joined by fibrous tissue; no joint

cavity– Cartilaginous joints: bones joined by cartilage; no joint

cavity– Synovial joints: joint cavity present

mainly axial skeleton

JOINTS (cont)

• FIBROUS– Sutures: seams of cranial bones;

(synostoses=fused bones)• coronal, lambdoid, sagital sutures

– Syndesmoses: bones connected by ligaments• between tibia and fibular, between radius & ulna

– Gomphoses: peg-in-socket; fibrous• teeth in the alveolar socket

JOINTS (cont)

• CARTILAGINOUS– Synchondroses: bones joined by hyaline

cartilage• eg-epiphyseal plate.

– Symphyses: fibrocartilage pad between• eg-pubic symphysis, intervertebral discs

Synovial Joints

• Those joints in which the articulating bones are separated by a fluid-containing joint cavity

• All are freely movable diarthroses

• Examples – all limb joints, and most joints of the body

Synovial Joints: General Structure

• Synovial joints all have the following– Articular cartilage– Joint (synovial) cavity– Articular capsule– Synovial fluid– Reinforcing ligaments

• nonaxial—slipping movements only

• uniaxial—movement in one plane

• biaxial—movement in two planes

• multiaxial—movement in three planes

•intercarpal•intertarsal•carpometacarpal•tarsometatarsal•vertebrocostal•intervertebral

•elbow•interphalangeal (finger; toe)•ankle (tib-fib w/ talus)•knee—modified hinge

•atlantoaxial•radioulnar

•radiocarpal•knuckle(metacarpophalangeal)•metatarsophalangeal

•thumb (carpometacarpal)

•shoulder (glenohumeral)•hip (coxal)

Fig. 38.16, p. 656

muscle

tendon

bursae

synovialcavity

muscle

vein

artery

femur

patella

fat pad

ligament

tibia