JOINTS OF THE SKELETAL SYSTEM

FUNCTIONS OF JOINTS

Bind parts of the skeletal system

Allow bone growth

Allow growth of the brain

Allow changes in shape during childbirth

Enable movement

CLASSIFICATION OF JOINTS

Based On MovementSynarthrotic—immovable

Sutures of skullAmphiarthrotic—slightly movable

Distal tibiofibular articulationDiarthrotic—freely movable

Knee

CLASSIFICATION OF JOINTS

Based on Construction Materials Fibrous

CT holds bones together (distal tibiofibular joint)

Cartilaginous Hyaline or fibrocartilage hold bones together (between

manubrium and first rib)

Synovial Presence of synovial membrane (knee)

FIBROUS JOINTS

Dense CT holds bones together

TypesSyndesmosisSutureGomphosis

(Fibrous) Syndesmosis

Distal end of tibia and fibula Amphiarthrotic

Suture

Skull Synarthrotic

Fibrous Joint

Gomphosis

Tooth in its socket Synarthrotic

CARTILAGINOUS JOINTS

SynchondrosisHyaline cartilageEpiphyseal disk (synarthrotic)Manubrium-1st rib (synarthrotic)

SymphysisFibrocartilageSymphysis pubis (amphiarthrotic) Intervertebral disk (amphiarthrotic)

Synovial Joint

Diarthrotic—allow free movement

Structurally complex

Consist of:Articular cartilageJoint capsuleSynovial membrane Synovial fluid

SYNOVIAL JOINT

SYNOVIAL JOINTS

PIVOT

BALL and SOCKET

HINGE

CONDYLOID

SADDLE

GLIDING

Pivot: Radio-Ulnar Joint

Between the head of the radius and the radial notch of the ulna. Allows for pronation (palm turns posterior) and supination (palm turns anterior).

Range of Movement

Abduction-AdductionAbduction is limited by greater trochanter

hitting acetabulum

Flexion-Extension

Lateral, Medial Rotation

Ball and socket: Shoulder

Shoulder Movements

Movement in 3 planes: Abduction - away from the body until vertical.

Adduction -brings arms back toward body. Rotation

Extensive range comes at the expense of joint stability. Rotator cuff muscles--movement and stabilization of the joint.

Hinge Joint

Cartilage

Condyloid: Radio-Carpal

Radius: Scaphoid, lunate, triquetral

Wrist Movements

Flexion-Extension

Abduction, Adduction

Articulations involvedRadioulnar IntracarpalRadiocarpal

Metacarpophalangeal Joint

CondyloidFlexionExtensionAbductionAdduction

Saddle Joint

FlexionExtensionAbductionAdduction

GLIDING JOINT

Movements

More Movements

Still More Movements