Anatomy and Physiology: Joints, Movements, and Joint Disorders

Vocabulary flashcards covering structural joint classifications, synovial joint types, joint movements, and related musculoskeletal pathologies from the lecture notes.

Syndesmosis

A tight union joint where bones are fastened together with a band or sheath of ligament, such as between the tibia and fibula.

Symphysis

A tough cartilaginous joint meaning 'growing together', such as the pubic symphysis connecting the pelvis, which is stronger than hyaline cartilage.

Articular capsule

A structure that forms around a joint and within the joint space in a synovial joint.

Articular cartilage

Cartilage that non-continuously covers the surface of a long bone at a joint.

Synovial membrane

The internal lining of the articular capsule that produces a viscous lubricating fluid to nourish cartilage.

Synovial fluid

A viscous lubricating fluid secreted by the synovial membrane that nourishes all cartilage within synovial joints.

Tendons

Dynamic stabilizers crossing a joint, consisting of the muscle portion that inserts into another bone.

Bursa

A fluid-filled cushion (subcutaneous, submuscular, or subtendinous) that acts to decrease friction between moving structures across a joint.

Tendon sheath

A protective sheath wrapped around muscle tendons crossing active joints, preventing the tendon from jamming against bone during movement.

Bursitis

Irritation or inflammation of a bursa, commonly resulting from overuse trauma or direct, sustained pressure.

Pivot joint

A synovial joint allowing rotation around an axis, found in the radioulnar joint and the atlantoaxial joint ($C1$ and $C2$).

Hinge joint

A joint that allows bending or straightening around a single axis, such as the humeroulnar joint (elbow) and tibiofemoral joint (knee).

Condyloid joint

A biaxial joint where a shallow depression articulates with a rounded structure, allowing two ranges of motion.

Saddle joint

A biaxial joint with concave and convex surfaces, located between the trapezium carpal bone and the first metacarpal bone of the thumb.

Plane joints

Also called gliding joints; multiaxial joints that allow micro-gliding movements between short bones in the wrist ($8$ bones) and ankle ($7$ bones).

Ball and socket joint

A multiaxial joint where a rounded head fits into a concave articulation, providing high mobility in the hip and shoulder joints.

Osteoarthritis

A wear-and-tear arthritis marked by increased synovial fluid and joint pressure, causing bone thickening according to Wolff's Law.

Wolff's Law

The principle that increased stress or pressure placed through a bone forces new bone to build and tissue to thicken.

Gout

A joint condition caused by microscopic, sharp, needle-like uric acid crystal depositions, commonly presenting first in the big toe.

Flexion

The closing of a joint or decrease in joint angle within the sagittal plane.

Extension

The opening of a joint or increase in joint angle within the sagittal plane.

Abduction

The opening of a joint in the coronal (frontal) plane, present in ball-and-socket joints of the hip and shoulder.

Adduction

The closing of a joint in the coronal (frontal) plane toward the body.

Pronation

Turning the hands downward at the radioulnar pivot joint.

Supination

Turning the hands upward (as if holding soup) at the radioulnar pivot joint.

Dorsiflexion

Bringing the ankle upward, pulling the toes toward the face.

Plantar flexion

Pushing the foot downward toward the ground, as when pressing a gas pedal.

Opposition

A special movement of the thumb bringing it toward the other fingers.

Reposition

The movement returning the thumb back to its anatomical position after opposition.

High ankle sprain

An injury involving tearing of the interosseous membrane and syndesmosis joint connecting the tibia and fibula above the ankle.