Joints

Flashcards about Joints from Anatomy and Physiology Lecture

Joint

A point of contact between two or more bones, cartilage and bone, or teeth and bone; also called articulation or arthrosis.

Classification of Joints

Joints can be classified structurally based on the presence of a joint cavity and the type of connective tissue involved, and functionally based on the degree of movement permitted.

Fibrous Joints

No articular cavity; articulating bones held together by dense irregular connective tissue; little or no movement; examples include sutures, syndesmosis, and gomphosis.

Cartilaginous Joints

No articular cavity; articulating bones held together by hyaline or fibrous cartilage; little or no movement; examples include synchondrosis and symphysis.

Synovial Joints

Have an articular capsule; permit a large range of movement; characterized by a synovial cavity and articular cartilage; may contain accessory ligaments, articular discs, and bursae.

Gliding

Movement of relatively flat bone surface back-and-forth and side-to-side over another; little change in angle between bones.

Angular

Increase or decrease in angle between bones.

Flexion

Decrease in angle between articulating bones, usually in the sagittal plane or an anterior movement at a ball-and-socket joint.

Lateral Flexion

Movement of trunk in frontal plane.

Extension

Increase in angle between articulating bones, usually in the sagittal plane or a posterior movement at a ball-and-socket joint.

Abduction

Movement of bone away from midline, usually in coronal plane.

Adduction

Movement of bone toward midline, usually in coronal plane.

Circumduction

Flexion, abduction, extension, adduction, and rotation in succession (or in the opposite order); distal end of body part moves in a circle.

Rotation

Movement of bone around longitudinal axis; in limbs, may be medial (toward midline) or lateral (away from midline).

Elevation

Superior movement of body part.

Depression

Inferior movement of body part.

Protraction

Anterior movement of body part in transverse plane.

Retraction

Posterior movement of body part in transverse plane.

Inversion

Medial movement of sole.

Eversion

Lateral movement of sole.

Dorsiflexion

Bending foot in direction of dorsum (superior surface).

Plantar Flexion

Bending foot in direction of plantar surface (sole).

Supination

Movement of forearm that turns palm anteriorly.

Pronation

Movement of forearm that turns palm posteriorly.

Opposition

Movement of thumb across palm to touch fingertips on same hand.

Plane Joint

Articulated surfaces flat or slightly curved. Many are biaxial: back-and-forth and side-to-side movements. Some are triaxial.

Hinge Joint

Convex surface fits into concave surface. Uniaxial: flexion-extension.

Pivot Joint

Rounded or pointed surface fits into ring formed partly by bone and partly by ligament. Uniaxial: rotation.

Ellipsoid Joint (Condyloid)

Oval-shaped projection fits into oval-shaped depression. Biaxial: flexion-extension, abduction-adduction.

Saddle Joint

Articular surface of one bone is saddle-shaped; articular surface of other bone "sits" in saddle. Biaxial: flexion-extension, abduction-adduction.

Ball-and-Socket Joint

Ball-like surface fits into cuplike depression. Triaxial: flexion-extension, abduction-adduction, rotation.

Bursae

Sac-like structures filled with synovial fluid that cushion movement of one body part over another.

Tendon Sheaths

A tube-like bursae that wraps around tendons subject to a great deal of friction.

Syndesmosis

Articulating bones united by a varying amount of dense irregular connective tissue, usually a ligament or membrane. Slightly movable.

Synchondrosis

Connecting material: hyaline cartilage. Slightly movable to immovable.

Symphysis

Connecting material: broad, flat disc of fibrous cartilage. Slightly movable to immovable.

Aging Effects on Joints

Decreased production of synovial fluid, thinning of articular cartilage, and loss of ligament length and flexibility.

Arthroplasty

Joint replacement surgery to counter some of the effects of aging on joints.

Tenosynovitis

Inflammation of a tendon sheath.