Comprehensive Guide to Joints and Their Disorders

Vocabulary flashcards covering joint classifications, features, movements, specific joints, stability factors, and common disorders.

Joint (Articulation)

A junction between two or more bones that allows movement and/or provides stability.

Fibrous Joint

connected by dense fibrous connective tissue, lack a joint cavity; generally immovable.

Suture

Fibrous joint between cranial bones; immovable in adults.

Gomphosis

Peg-in-socket fibrous joint binding a tooth to its socket via periodontal ligament.

Syndesmosis

Fibrous joint with ligament or interosseous membrane allowing slight movement (e.g., radius–ulna).

Cartilaginous Joint

Joint united by cartilage (hyaline or fibrocartilage) without a cavity; slightly movable.

Synchondrosis

Cartilaginous joint of hyaline cartilage, such as the epiphyseal plate in growing bones.

Symphysis

Cartilaginous joint of fibrocartilage permitting slight movement, e.g., pubic symphysis, intervertebral discs.

Synovial Joint

Freely movable joint (diarthrosis) featuring a fluid-filled cavity.

Articular Cartilage

Hyaline cartilage covering bone ends in synovial joints, reducing friction.

Synovial Fluid

Viscous fluid in joint cavity that lubricates and nourishes articular cartilage.

Articular Capsule

Two-layer enclosure of a synovial joint consisting of an outer fibrous layer and inner synovial membrane.

Reinforcing Ligament

Band of dense connective tissue that strengthens and stabilizes a synovial joint.

Synarthrotic Joint

Immovable joint (e.g., sutures).

Amphiarthrotic Joint

Slightly movable joint (e.g., pubic symphysis).

Diarthrotic Joint

Freely movable joint (e.g., shoulder).

Articular Shape

Contour of bone surfaces; contributes minimally to joint stability.

Ligament (in stability)

Dense connective band whose number and placement enhance joint stability.

Muscle Tone

Continuous mild contraction of muscles; most critical factor for joint stability.

Gliding Movement

Nonaxial sliding of flat bone surfaces, as in wrist carpals.

Flexion

Angular movement decreasing the angle between bones in the sagittal plane.

Extension

Angular movement increasing the angle between bones in the sagittal plane.

Abduction

Movement of a limb away from the body midline in the frontal plane.

Adduction

Movement of a limb toward the body midline in the frontal plane.

Rotation

Turning a bone around its longitudinal axis; may be medial or lateral.

Supination

Forearm movement turning palm anteriorly or upward.

Pronation

Forearm movement turning palm posteriorly or downward.

Dorsiflexion

Bending the foot upward toward the shin.

Plantarflexion

Pointing the foot downward away from the shin.

Inversion

Turning the sole of the foot medially.

Eversion

Turning the sole of the foot laterally.

Protraction

Anterior movement of a body part in a transverse plane.

Retraction

Posterior movement of a body part in a transverse plane.

Elevation

Lifting a body part superiorly.

Depression

Lowering a body part inferiorly.

Opposition

Touching the thumb to fingertips, enabling grasping.

Uniaxial Joint

Synovial joint permitting movement in one plane (e.g., hinge, pivot).

Biaxial Joint

Synovial joint permitting movement in two planes (e.g., condylar, saddle).

Multiaxial Joint

Synovial joint moving in multiple planes (e.g., ball-and-socket).

Nonaxial Joint

Synovial joint with slipping movements only (e.g., plane joints).

Plane Joint

Synovial joint with flat surfaces allowing gliding (e.g., intercarpals).

Hinge Joint

Uniaxial synovial joint allowing flexion and extension (e.g., elbow).

Pivot Joint

Uniaxial synovial joint enabling rotation around a single axis (e.g., atlantoaxial).

Condylar Joint

Biaxial synovial joint permitting flexion/extension and abduction/adduction (e.g., knuckles).

Saddle Joint

Biaxial synovial joint with concave-convex surfaces; allows opposition (e.g., thumb carpometacarpal).

Ball-and-Socket Joint

Multiaxial synovial joint permitting movement in all planes (e.g., shoulder, hip).

Temporomandibular Joint (TMJ)

Combined hinge and gliding joint enabling jaw movements; prone to dislocation and TMJ disorders.

Glenohumeral (Shoulder) Joint

Ball-and-socket joint reinforced by rotator cuff muscles and ligaments; highly mobile but less stable.

Elbow Joint

Hinge joint stabilized by ulnar and radial collateral ligaments; permits flexion and extension.

Hip Joint

Ball-and-socket joint secured by iliofemoral, pubofemoral, ischiofemoral ligaments and ligamentum teres; more stable than shoulder.

Knee Joint

Complex hinge joint with menisci, collateral ligaments, ACL, and PCL; allows flexion, extension, slight rotation.

Meniscus

Crescent-shaped fibrocartilage pad in the knee that cushions and stabilizes.

Anterior Cruciate Ligament (ACL)

Knee ligament preventing anterior displacement of the tibia.

Posterior Cruciate Ligament (PCL)

Knee ligament preventing posterior displacement of the tibia.

Cartilage Tear

Injury from compression or stress causing pain, swelling, and joint locking; often requires surgery.

Sprain

Ligament stretch or tear causing pain and instability; common in ankles and knees.

Dislocation

Bone displacement from its joint; requires reduction to realign.

Bursitis

Inflammation of bursae leading to pain and swelling; treated with rest and anti-inflammatories.

Tendinitis

Inflammation of a tendon due to overuse, causing pain and tenderness.

Osteoarthritis (OA)

Degenerative joint disease with cartilage breakdown and bone spur formation; related to aging.

Rheumatoid Arthritis (RA)

Chronic autoimmune inflammation of synovial membranes causing pain and deformity.

Gout

Arthritis caused by uric acid crystal deposition, often in the big toe; triggers sudden severe pain.

Lyme Disease

Tick-borne infection that can mimic joint disorders; characterized by rash, fever, fatigue; treated with antibiotics.