Chapter 9 Articulations

Synarthroses

immovable joint

Amphiarthrosis

slightly movable joint

Diarthroses

freely movable joints

Sutures

fibrous, immovable joints between the bones of the skull

Synostoses

fused bony joints, e.g. epiphyseal lines

Syndesmosis

slightly movable joints; bones united by fibrous connective tissue, e.g. ligament between fibula and tibia

Gomphosis

A type of fibrous joint such as a tooth into the alveolus

Periodontal ligament

Holds tooth in the socket

Symphyses

Bones united by fibrocartilage; e.g. intervertebral discs and the pubic symphysis

Synovial joints

freely movable joints

Uniaxial (monoaxial) movement

synovial joint motion; movement in one plane (ex. hinge joint; pivot joint)

Biaxial movement

synovial joint motion; movement in two planes (ex. ellipsoidal joint, saddle joint)

Multiaxial movement

movement in or around all three planes of space and axes (gliding joints)

Triaxial movement

synovial joint that allows movements at all angles (e.g. ball and socket joints; shoulder and hip joints)

Articular cartilage

covers the surfaces of bones where they come together to form joints; similar to hyaline cartilage

Joint (articular) cavity

A space between the articulating bones. The cavity is filled with synovial fluid

Articular capsule

connective tissue structure that encloses the joint cavity of a synovial joint

Fibrous layer of the periosteum

outer layer consisting of dense irregular connective tissue consisting of Sharpey's fibers that secure to bone matrix

Synovial membrane

lines the capsule and secretes synovial fluid

Synovial fluid

Secretion of synovial membranes that lubricates joints and nourishes articular cartilage

Capsular ligaments

surround the synovial joints between adjacent articular processes inferiorly and superiorly

Articular discs/menisci

Fibrocartilage separates articular surfaces to improve "fit" of bone ends, stabilize joint, and reduce wear and tear

Bursae

fluid filled sacs between skin and bone that reduce friction and cushion

Tendon sheath

an elongated bursa that wraps completely around a tendon subjected to friction

Origin

attachment of a muscle that remains relatively fixed during muscular contraction

Insertion

The attachment of a muscle tendon to a moveable bone or the end opposite the origin

Gliding

nearly flat bone surfaces slide or glide over each other found the wrist and ankle

Flexion

Decreases the angle of a joint

Extension

increases the angle of a joint

Hypertension

higher than normal blood pressure

Abduction

movement away from the midline

Adduction

movement toward the midline

Circumduction

circular movement of a limb

Rotation

circular movement around an axis such as the shoulder joint

Supination

lying on the back or turning palm up

Pronation

lying on the stomach; turning the palm downward

Dorsiflexion

movement that bends the foot upward at the ankle

Plantar flexion

bends the foot downward at the ankle

Inversion

Turning the sole of the foot inward

Eversion

turning the sole of the foot outward

Protraction

mandible juts out

Retraction

mandible is pulled toward neck

Depression

lowering a part (drooping the shoulders)

opposition

Movement of the thumb to touch the fingertips

Shoulder dislocations

Fall on outstretched arm, direct blow to posterior humerus
Weak joint, traumatic force on rotated joint

Elbow joint

hinge joint formed by humerus, ulna, and radius

Semilunar cartilage

meniscus; one of the cartilages of the knee joint; crescent-shaped/cushions joint, protects end of bone

Cartilage tears

Occur when a meniscus is subjected to compression and shear stress at the same time
Fragments may cause joint to lock or bind
Cartilage rarely repairs itself
Repaired with arthroscopic surgery

Sprains

Injuries caused by sudden twisting or wrenching of a joint with stretching or tearing of ligaments

Bursitis

inflammation of a bursa usually caused by a blow or friction

Tendonitis

inflammation of a tendon

Arthritis

painful inflammation and stiffness of the joints.

Osteoarthritis

degenerative joint disease

Rheumatoid Arthritis

a chronic autoimmune disorder in which the joints and some organs of other body systems are attacked

Synovitis

inflammation of the synovial membrane that results in swelling and pain of the affected joint

Elevation

raising a part (shrugging the shoulders)