Human Anatomy and Physiology Third Edition Chapter 8 Articulations

These vocabulary flashcards cover the functions, classifications, movements, and specific anatomical structures of human joints as presented in Chapter 8.

Joints (Articulations)

Structures that connect two bones and fulfill functions such as enabling movement, providing stability, and allowing long bones to lengthen via the Epiphyseal Plate.

Synarthrosis

A functional classification of joints that allows no movement between articulating bones and provides the most stability.

Amphiarthrosis

A functional classification of joints that allows a small amount of movement between articulating bones and provides a significant amount of stability.

Diarthrosis

A functional classification of joints that is freely moveable with a wide variety of specific movements and provides the least amount of stability.

Fibrous Joints

Joints united by dense regular collagenous connective tissue with no joint space; functionally classified as synarthroses or amphiarthroses.

Cartilaginous Joints

Joints characterized by cartilage between the articulating bones and no joint space; functionally classified as synarthroses or amphiarthroses.

Synovial Joints

Joints that have a joint cavity filled with fluid between articulating bones and are functionally classified as diarthroses.

Sutures

Very stable synarthroses between bones of the skull where finger-like projections interweave and are held together by short collagen fibers; may fuse into a Synostosis during the $4^{th}$ or $5^{th}$ decade of life.

Gomphoses

A stable synarthrosis joint between a tooth and its corresponding alveolus in the mandible or maxilla, attached by the Periodontal Ligament.

Syndesmoses

Amphiarthroses joints where articulating bones are joined by an Interosseous Membrane or Ligament, such as between the radius and ulna.

Synchondroses

Cartilaginous joints united by Hyaline Cartilage that function as synarthroses, such as the epiphyseal plate or the first sternocostal joint.

Symphyses

Cartilaginous joints united by a Fibrocartilage Pad that function as amphiarthroses, such as intervertebral joints and the pubic symphysis.

Articular Capsule

A double-layered structure in synovial joints consisting of an Outer Fibrous Layer of dense irregular connective tissue and an Inner Synovial Membrane of loose connective tissue.

Synovial Fluid

Fluid secreted by the synovial membrane that provides lubrication, metabolic functions (supplying glucose and removing wastes), and shock absorption.

Articular Cartilage

Avascular hyaline cartilage that covers all exposed articulating bone surfaces within a joint cavity to reduce friction and absorb shock.

Intrinsic Ligaments

Thickened regions of the articular capsule found within the capsule itself.

Extrinsic Ligaments

Ligaments that are not part of the articular capsule and may be found inside or outside the joint cavity.

Bursae

Synovial fluid-filled structures lined with a synovial membrane found in high-stress regions to minimize friction between bones, tendons, muscles, and skin.

Bursaitis

Inflammation of a bursa commonly resulting from traumatic events, repetitive movements, or inflammatory disease.

Osteoarthritis

The most common form of arthritis resulting from wear and tear, injuries, and advanced age.

Rheumatoid Arthritis

An autoimmune disease resulting in joint destruction mediated by the individual’s own immune system.

Gouty Arthritis (Gout)

Joint damage caused by an inflammatory reaction to excess Uric Acid Crystal deposits.

Nonaxial Joints

Joints where motion occurs in one or more planes but does not move around an axis.

Uniaxial Joints

Joints that allow motion around $1$ axis.

Biaxial Joints

Joints that allow motion around $2$ axes.

Multiaxial (Triaxial) Joints

Joints that allow motion around $3$ axes.

Flexion

An angular movement that decreases the angle between articulating bones by bringing them closer together.

Extension

An angular movement that increases the angle between articulating bones.

Abduction

Motion of a body part away from the midline of the body or another reference point.

Adduction

Motion of a body part toward the midline of the body or another reference point.

Circumduction

A cone-shaped motion where a freely moveable distal bone moves around a stationary proximal bone.

Rotation

A nonangular, pivoting motion where a bone turns around its own Longitudinal Axis.

Opposition

A special movement occurring at the thumb involving movement across the palmar surface of the hand.

Inversion

A rotational movement of the foot in which the plantar surface rotates medially toward the midline.

Dorsiflexion

A movement where the angle between the foot and the tibia decreases, pulling the toes toward the head.

Supination

A movement of the forearm where the palm faces anteriorly with the thumb pointing laterally.

Hinge Joint

A uniaxial synovial joint where the convex surface of one bone fits into a concave depression of another bone.

Condylar (Ellipsoid) Joint

A biaxial synovial joint where an oval, convex surface of one bone fits into a shallow concave surface of another.

Ball-and-Socket Joint

A multiaxial synovial joint where a spherical bone surface fits into a cup or socket, such as the shoulder or hip.

Humeroulnar Joint

One of the two articulations of the elbow, located between the trochlea of the humerus and the trochlear notch of the ulna.

Anular Ligament

A ligament in the elbow joint that stabilizes the radial head.

Tibiofemoral Joint

An articulation in the knee joint located between the femoral and tibial condyles.

Menisci

C-shaped fibrocartilage pads on the tibial condyles that improve bone fit, provide shock absorption, and cushioning.

Anterior Cruciate Ligament (A C L)

A ligament running from the anterior tibia to the posterior femur that prevents the tibia from moving too far anteriorly.

Unhappy Triad

A knee injury involving the simultaneous rupture of the tibial collateral ligament, the medial meniscus, and the anterior cruciate ligament.

Glenohumeral Joint

The shoulder joint, which is the most freely moveable and unstable joint in the body.

Rotator Cuff

A group of four muscle tendons that reinforce the shoulder joint: Subscapularis, Supraspinatus, Infraspinatus, and Teres Minor.

Glenoid Labrum

A fibrocartilaginous ring that sits on the rim of the glenoid cavity to support the shoulder joint.

Acetabular Labrum

A fibrocartilage ring that strengthens the fit between the acetabulum and the head of the femur in the hip joint.

Ligament of the Head of the Femur

A ligament that links the center of the head of the femur with the acetabulum.