Chapter 9 - Articulations

Comprehensive vocabulary flashcards covering the structural and functional classifications of joints, types of synovial motion, specific joint anatomy, and common arthritic conditions.

Articulation

The place of contact between bones, between bone and cartilage, or between bones and teeth; also called a joint.

Relationship between Mobility and Stability

A structural rule where a more mobile joint is conversely less stable.

Synarthrosis

An immovable joint representing a very strong union where movement between bones must be prevented.

Amphiarthrosis

A slightly movable joint that is stronger than a diarthrosis; articulating bones are connected by collagen fibers or cartilage.

Diarthrosis

A freely movable joint, also known as a synovial joint, typically located at the ends of long bones.

Fibrous Joint

A structural classification where bones are held together by dense regular (fibrous) connective tissue with no joint cavity.

Cartilaginous Joint

A structural classification where bones are joined by cartilage and lack a joint cavity.

Synovial Joint

A structural classification featuring a fluid-filled synovial cavity, a joint capsule, and various ligaments.

Suture

A fibrous joint found only in the skull where bones are interlocked and bound by dense fibrous connective tissue.

Gomphosis

A fibrous connection involving the periodontal ligament that binds teeth to their sockets.

Syndesmosis

A fibrous joint where articulating bones are joined by ligaments only, such as between the radius and ulna.

Synchondrosis

A rigid cartilaginous bridge between two bones, classified as a synarthrotic joint (e.g., epiphyseal cartilage of long bones).

Symphysis

A cartilaginous joint classified as amphiarthrotic where bones are separated by a pad of fibrocartilage (e.g., pubic symphysis).

Synovial Fluid

Fluid produced by the synovial membrane that fills the joint cavity to reduce friction during movement.

Articular Cartilage

Hyaline cartilage covering articulating surfaces that prevents bones from touching and reduces friction.

Ligament

Connective tissue that joins bone to bone to support and strengthen joints.

Bursa

A fibrous, saclike structure containing synovial fluid that cushions areas where tendons or ligaments rub.

Fat pads

Masses of adipose tissue that act as packing material and provide protection for the joint cavity as it changes shape.

Tendon

A structure that attaches a muscle to a bone and helps stabilize the joint.

Uniaxial

A synovial joint classification where the bone moves in just one plane.

Biaxial

A synovial joint classification where the bone moves in two planes.

Multiaxial

A synovial joint classification (also called triaxial) where the bone moves in multiple planes.

Planar (Gliding) Joint

A synovial joint with flattened or slightly curved faces that slide across each other with very limited motion.

Hinge Joint

A synovial joint permitting angular motion in a single plane (monaxial), similar to opening and closing a door.

Pivot Joint

A synovial joint that allows rotation only (monaxial).

Condyloid (Ellipsoid) Joint

A synovial joint with an oval articular face within a depression, allowing motion in two planes (biaxial).

Saddle Joint

A synovial joint with two concave faces that are straddled, allowing biaxial movement (e.g., sternoclavicular joint).

Ball-and-Socket Joint

A triaxial synovial joint where a round head rests within a cup-shaped depression, providing a full range of motion.

Flexion

An angular motion that decreases the angle between two articulating bones.

Extension

An angular motion that increases the angle between two articulating bones.

Abduction

Movement in the frontal plane away from the longitudinal axis of the body.

Adduction

Movement in the frontal plane toward the longitudinal axis of the body.

Circumduction

A complex movement involving flexion, abduction, extension, and adduction resulting in a circular motion without rotation.

Pronation

A medial (inward) rotation where the wrist/hand moves from the anatomical position to facing backward.

Supination

A lateral (outward) rotation where the wrist/hand moves from facing backward to the anatomical position.

Dorsiflexion

Special movement involving flexion at the ankle, characterized by lifting the toes.

Plantar flexion

Special movement involving extension at the ankle, characterized by pointing the toes.

Opposition

A special movement of the thumb toward the palm that enables the ability to grasp/hold objects.

Rotator Cuff

A group of 4 muscles (Supraspinatus, Infraspinatus, Teres minor, and Subscapularis) that support the shoulder joint and limit movement.

Ligaments of the Knee

Seven supporting structures including the Anterior cruciate ligament (ACL) and Posterior cruciate ligament (PCL) which maintain femoral and tibial alignment.

Rheumatoid Arthritis (RA)

A chronic inflammatory autoimmune disease affecting $2.5\%$ of the adult population where the body attacks its own tissues, causing ossification and immobilization.

Osteoarthritis (OA)

The most common type of arthritis, usually in people over age 60, caused by wear and tear of joint surfaces leading to bone rubbing on bone.

Gouty Arthritis

A condition occurring when crystals of uric acid or calcium salts form within synovial fluid due to metabolic disorders.