JOINTS

a.k.a. articulations Functional junctions between bones Bind parts of the skeletal system Make bone growth possible Permit parts of the skeleton to change shape during childbirth Enable the body to move in response to skeletal muscle contractions Immovable, slightly movable, or freely movable

Types Fibrous – lie between bones that closely contact one another no appreciable movement takes place Ex. Sutures in the skull

Cartilaginous – composed of hyaline cartilage or fibrocartilage Slight flexibility Ex. Intervertebral disks, symphysis pubis, first rib with the sternum

Synovial – allow free movement Articular ends are covered with hyaline cartilage and a surrounding capsule of dense connective tissue holds them together Synovial membraneous lining secretes synovial fluid which lubricates joints Have shock-absorbing pads called menisci Have fluid-filled sacs called bursae

Type of Synovial Joints Ball-and-socket – shoulder and hip Condyloid – joints between metacarpals and phalanges (oval-shaped condyle of one bone fits into an elliptical cavity of another bone) Gliding – wrist and ankle (nearly flat or slightly curved) Hinge – elbow and phalanges Pivot – proximal ends of the radius and ulna Saddle – carpal and metacarpal (both concave and convex surfaces)

Type of Joint Movements (p.157-159) Flexion Extension Dorsiflexion Plantar flexion Hyperextension Abduction Adduction Rotation Circumduction Pronation Supination Eversion Inversioln Retraction Protraction Elevation depression