Articulations and Range of Motion

dorsiflexion

Lifting the foot so that its superior surface approaches the shin (corresponds to wrist extension)

Protraction

Nonangular anterior movements in a transverse plane

Retraction

Nonangular posterior movements in a transverse plane

plantar flexion

depressing the foot (pointing the toes)

supination

Rotating the forearm laterally so that the palm faces anteriorly or superiorly

Flexion

a bending movement, usually along the sagittal plane, that decreases the angle of the joint and brings the articulating bones closer together.

epiphyseal (growth) plate

a disc of hyaline cartilage that grows during childhood to lengthen the bone

Joint Cavity

a feature unique to synovial joints; a potential space that contains a small amount of synovial fluid

periosteum

a glistening white, double-layered membrane that covers the external surface of the entire bone except the joint surfaces

synovial

articulating bones are separated by a fluid-filled cavity. Most joints are this way. Examples: gliding, condyloid, ball-and-socket, hinge, saddle, pivot

epiphysis

bone ends

synchondroses

cartilaginous; joints between the shafts and the epiphyseal plates of long bones

symphyses

cartilaginous; pads of fibrous cartilage cushions joint Examples: pubic symphysis, intervertebral joints

articular cartilage

covers the ends of most bones at movable joints

sutures

fibrous; b/w bones of skull (in adults, fibrous tissue ossifies creating synostoses)

syndesmoses

fibrous; junction of bones held together by ligaments Examples: tibia-fibula; radius-ulna; (distal ends)

gomphoses

fibrous; tooth attached to socket with periodontal ligament

diarthroses

freely movable joints

synarthroses

immovable joints

Abduction

movement of a limb away from the midline or median plane of the body, along the frontal plane

Circumduction

moving a limb so that it describes a cone in space; distal end of the limb moves in a circle, while the point of the cone (the shoulder or hip joint) is more or less stationary

Extension

reverse of flexion and occurs at the same joints; involves movement along the sagittal plane that increases the angle between the articulating bones and typically straightens a flexed limb or body part

diaphysis

shaft that forms the long axis of the bone, composed of a relatively thick collar of compact bone

amphiarthroses

slight movable joints

pronation

the forearm rotates medially and the palm faces posteriorly or inferiorly.

Adduction

the opposite of abduction, so it is the movement of a limb toward the body midline or, in the case of the digits, toward the midline of the hand or foot

Rotation

the turning of a bone around its own long axis

synovial fluid

viscous, egg-white consistency; provides slippery, weight-bearing film that reduces friction b/w the cartilages

meniscus (articular disc)

wedges of fibrocartilage separating the articular surfaces