Articulations & Synovial Joints Lecture

Vocabulary flashcards covering joint classifications, structures, movements, and related pathologies from the lecture.

Articulation

A joint; the location where two or more bones meet and interact.

Range of Motion (ROM)

The amount of movement permitted at a joint.

Synarthrosis

An immovable joint, such as cranial sutures or tooth sockets.

Amphiarthrosis

A slightly movable joint connected by cartilage or collagen, e.g., pubic symphysis.

Diarthrosis

A freely movable joint; synonymous with synovial joint.

Suture

Fibrous joint stitching skull bones together; classified as synarthrosis.

Gomphosis

Peg-in-socket fibrous joint securing a tooth in the mandible or maxilla.

Syndesmosis

Fibrous joint where bones are linked by a ligament or interosseous membrane.

Synovial Joint

Freely movable joint with a capsule, synovial membrane, and synovial fluid.

Articular Cartilage

Smooth hyaline cartilage covering bone ends to reduce friction in a joint.

Joint Capsule

Fibrous sac enclosing a synovial joint, continuous with periosteum.

Synovial Membrane

Inner lining of a joint capsule that secretes synovial fluid.

Synovial Fluid

Viscous fluid providing lubrication, nutrient distribution, and shock absorption.

Bursa

Small fluid-filled pillow reducing friction between bones, tendons, or skin.

Fat Pad

Localized adipose tissue within a joint that cushions and fills spaces.

Meniscus

C-shaped fibrocartilage pad that improves fit and absorbs shock, e.g., in the knee.

Tendon

Connective tissue cord linking muscle to bone.

Ligament

Dense connective tissue band linking bone to bone and stabilizing joints.

Hinge Joint

Synovial joint allowing movement like a door (flexion/extension), e.g., elbow.

Ball-and-Socket Joint

Most mobile synovial joint; spherical head fits into cup, e.g., shoulder, hip.

Pivot Joint

Synovial joint allowing rotation, e.g., atlas rotating on axis (C1–C2).

Gliding Joint

Synovial joint with flat surfaces sliding past each other, e.g., clavicle–manubrium.

Condylar Joint

Oval articular surface fits into depression on another bone, e.g., metacarpophalangeal joints.

Saddle Joint

Articulating surfaces shaped like rider and saddle, e.g., thumb (trapezium-first metacarpal).

Flexion

Movement that decreases the angle between two bones.

Extension

Movement that increases the angle between two bones.

Abduction

Movement away from the body’s midline.

Adduction

Movement toward the body’s midline.

Circumflexion

Circular, conical motion of a limb around a joint.

Pronation

Rotating forearm to turn palm downward or posteriorly.

Supination

Rotating forearm to turn palm upward or anteriorly.

Opposition

Thumb movement toward the palm or fingers for grasping.

Inversion

Turning sole of the foot medially (common ankle-sprain position).

Eversion

Turning sole of the foot laterally.

Dorsiflexion

Lifting the foot so toes point upward while heel stays down.

Plantar Flexion

Pointing toes downward; pressing foot into the ground.

Protraction

Anterior (forward) movement of a body part, e.g., jutting the jaw.

Retraction

Posterior (backward) movement of a body part, e.g., pulling the jaw in.

Elevation (Jaw)

Closing the mouth by raising the mandible.

Depression (Jaw)

Opening the mouth by lowering the mandible.

Annulus Fibrosus

Tough outer ring of fibrocartilage in an intervertebral disc.

Nucleus Pulposus

Gel-like inner core of an intervertebral disc that absorbs shock.

Bulging Disc

Nucleus pulposus distorts annulus fibrosus, causing disc to protrude outward.

Herniated Disc

Nucleus pulposus breaks through annulus fibrosus into vertebral canal, compressing nerves.

Osteopenia

Localized reduction in bone mass not severe enough to be osteoporosis.

Osteoporosis

Systemic metabolic disease characterized by porous, weakened bones prone to fracture.