Skeletal System - Articulations

Comprehensive vocabulary flashcards covering joint classifications, synovial structures, anatomical movements, specific articulations, and joint clinical conditions.

Articulations

Points where two bones meet, also known as joints.

Synarthrosis

The functional classification for an immovable joint.

Amphiarthrosis

The functional classification for a slightly movable joint.

Diarthrosis

The functional classification for a freely movable joint.

Fibrous joints

Structural classification where bones are held together by dense collagen fibers and lack a synovial cavity.

Cartilaginous joints

Structural classification where bones are held together by cartilage and lack a synovial cavity.

Synovial joints

Structural classification where bones are held together by ligaments, fluid, and capsules, having a joint cavity.

Sutures

Synarthrotic fibrous joints found only between bones of the skull with irregular, interlocking edges.

Syndesmoses

Amphiarthrotic fibrous joints where movement depends on fiber length, such as the tibiofibular ligament.

Gomphoses

Synarthrotic fibrous peg-in-socket joints, specifically the articulations of teeth with the sockets of the maxillae and mandible.

Synchondroses

Synarthrotic cartilaginous joints where the connecting tissue is hyaline cartilage, such as the epiphyseal plate.

Symphyses

Amphiarthrotic cartilaginous joints where bones are covered with hyaline cartilage but connected by a disc of fibrocartilage.

Articular Capsule

A sleeve-like structure enclosing the synovial cavity with an outer fibrous capsule and an inner synovial membrane.

Synovial Fluid

Fluid secreted by the synovial membrane that lubricates joints, prevents erosion, supplies nutrients, and contains phagocytic cells.

Articular discs (menisci)

Fibrocartilage that separates articular surfaces to improve the fit of bone ends and stabilize the joint.

Bursae

Bags of synovial fluid that reduce friction where ligaments, muscles, skin, tendons, or bones rub together.

Tendon sheaths

Elongated bursae wrapped completely around tendons that are subjected to friction.

Origin

The point of muscle attachment to an immovable bone.

Insertion

The point of muscle attachment to a movable bone.

Flexion

A movement that decreases the angle of a joint and brings two articulating bones closer together.

Extension

A movement that increases the angle of a joint and takes two articulating bones further away.

Abduction

Movement along the frontal plane away from the midline of the body.

Adduction

Movement along the frontal plane toward the midline of the body.

Circumduction

An angular movement that is a combination of flexion, extension, abduction, and adduction.

Rotation

Turning movement of a bone around its own longitudinal axis.

Elevation

Upward movement of a body part, such as closing the mouth.

Depression

Downward movement of a body part, such as opening the mouth.

Protraction

Movement of a part of the body anteriorly, such as thrusting the mandible forward.

Retraction

Movement of a protracted body part back to its normal position.

Inversion

Movement of the sole of the foot medially.

Eversion

Movement of the sole of the foot laterally.

Dorsiflexion

Bending of the foot at the ankle in an upward direction.

Plantar flexion

Bending of the foot at the ankle in a downward direction.

Supination

Movement of the forearm so that the palm is turned upward.

Pronation

Movement of the forearm so that the palm is turned downward.

Opposition

Movement of the thumb across the palm to touch the tips of the fingers on the same hand.

Anulus fibrosus

The outer portion of an intervertebral disc composed of fibrocartilage.

Nucleus pulposus

The inner gelatinous portion of an intervertebral disc composed of water and fibers.

Temporomandibular joint (TMJ)

A diarthrotic synovial hinge joint between the head of the mandible and the temporal bone.

Glenohumeral joint

A diarthrotic ball-and-socket joint between the head of the humerus and the glenoid cavity of the scapula; the most unstable joint in the body.

Radiocarpal joint

A diarthrotic condylar joint between the radius, an articular disc, and the proximal carpal bones (scaphoid, lunate, triquetrum).

Talocrural joint

A diarthrotic hinge joint composed of articulations between the talus and the distal ends of the tibia and fibula.

Gouty arthritis

A form of arthritis where urate crystals accumulate in synovial joints.

Osteoarthritis (OA)

A common degenerative joint disease resulting from wear-and-tear over time.

Rheumatoid arthritis (RA)

An autoimmune disease where immune cells target the body's own joint tissue.