Chapter 09A Skeletal System: Articulations

This set of vocabulary flashcards covers the classification (structural and functional), characteristics, and specific examples of joints in the skeletal system, including fibrous, cartilaginous, and synovial joints.

Joints (articulations)

Places of union between bones, bones and cartilage, or bones and teeth.

Arthrology

The study of joints.

Fibrous joint

A structural class where bones are held together by dense connective tissue and lack a joint cavity.

Cartilaginous joint

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

Synovial joint

A structural class where bones are joined by ligaments with a fluid-filled joint cavity separating bone surfaces.

Synarthroses

A functional class of immobile joints, which can be fibrous or cartilaginous.

Amphiarthroses

A functional class of slightly mobile joints, which can be fibrous or cartilaginous.

Diarthroses

A functional class of freely mobile joints; this includes all synovial joints.

Gomphoses

A 'peg in a socket' fibrous joint where teeth are held in place by fibrous periodontal ligaments in the mandible or maxillae.

Sutures

Fibrous joints found between some skull bones that have interlocking, irregular edges and function as synarthroses.

Syndesmoses

Fibrous joints bound by an interosseous membrane (broad ligamentous sheet) that function as amphiarthroses.

Synchondroses

Cartilaginous joints where bones are joined by hyaline cartilage and function as immobile synarthroses.

Symphyses

Cartilaginous joints featuring pads of fibrocartilage that act as shock absorbers and allow slight mobility (amphiarthroses).

Costochondritis

Inflammation of the costochondral joints causing localized chest pain, which may be mistaken for a myocardial infarction.

Articular cartilage

Avascular hyaline cartilage on bone surfaces at synovial joints that reduces friction, absorbs compression, and lacks a perichondrium.

Articular capsule (joint capsule)

A double-layered sleeve in synovial joints consisting of an outer fibrous layer and an inner synovial membrane.

Synovial membrane

The inner layer of the articular capsule composed of areolar connective tissue that helps produce synovial fluid.

Synovial fluid

A viscous, oily substance that lubricates articular cartilage, nourishes chondrocytes, and acts as a shock absorber.

Extrinsic ligaments

Ligaments that are physically separate from the articular capsule of a synovial joint.

Intrinsic ligaments

Ligaments that represent a thickening of the articular capsule itself.

Bursae

Fibrous, saclike structures containing synovial fluid and lined by synovial membrane that alleviate friction.

Tendon sheaths

Elongated bursae that wrap around tendons where friction is excessive, commonly found in the wrist and ankle.

Fat pads

Accessory structures in synovial joints that act as protective packing material and fill spaces when joint shape changes.

Uniaxial joint

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

Biaxial joint

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

Multiaxial (triaxial) joint

A synovial joint classification where the bone moves in multiple planes or axes.

Plane joint

The simplest and least mobile synovial articulation, featuring flat surfaces and uniaxial side-to-side gliding movement.

Hinge joint

A uniaxial synovial joint with a convex surface fitting into a concave depression.

Pivot joint

A uniaxial synovial joint where a bone with a rounded surface fits into a ligament ring, allowing rotation on a longitudinal axis.

Condylar joint

A biaxial synovial joint featuring an oval, convex surface articulating with a concave surface.

Saddle joint

A biaxial synovial joint with convex and concave surfaces resembling a saddle shape.

Ball-and-socket joint

The most freely mobile multiaxial synovial joint, featuring a spherical head of one bone fitting into a cuplike socket.