The term “articular” fundamentally means relating to a joint, or an articulation, in the body. Joints are specialized connections between bones that allow for varying degrees of movement, necessary for almost every physical action from walking to writing. This anatomical term acts as an adjective to classify any structure, surface, or condition directly associated with these complex junctures.
Defining Articular
The word “articular” is derived from the Latin term articulus, which translates to a small joint or a part of a limb between joints. In a biological context, the word serves to describe anything pertaining to the body’s joints or the act of joining two bones. This allows for clear, precise communication among health professionals when discussing specific parts of the musculoskeletal system.
For example, a doctor might refer to an “articular surface” to denote the specific area of bone where it meets another bone. Similarly, “articular movement” refers to the range of motion permitted by a particular joint structure. The term highlights the connection point between skeletal components.
Anatomy of an Articular Joint
The most common and functionally significant type of connection described by this term is the synovial joint, which includes the knee, hip, and shoulder. These joints are characterized by a joint cavity, which allows for free movement between the bones. The entire assembly is enclosed by an articular capsule, a fibrous envelope that provides structural support and stability.
Within this capsule, the opposing ends of the bones are covered in a smooth, resilient tissue known as articular cartilage. This tissue, typically hyaline cartilage, acts as a shock absorber and reduces friction as the bones move against each other. The cartilage is avascular, meaning it lacks a direct blood supply, and instead receives its nutrition from the fluid within the joint space.
The joint cavity itself is filled with synovial fluid, a thick, viscous substance secreted by the inner lining of the capsule, called the synovial membrane. Synovial fluid serves a triple function: it lubricates the articular surfaces, provides nutrients to the surrounding cartilage, and offers shock absorption. The combination of the capsule, cartilage, and fluid ensures that movement is smooth and non-painful.
Common Articular Conditions and Terminology
In medical practice, the term “articular” is frequently used to specify the location and nature of an illness or injury. The most common pathology is arthritis, which literally translates to joint inflammation. Different types of arthritis, such as osteoarthritis and rheumatoid arthritis, are classified as articular diseases because they primarily affect the joint structures.
A physician may also use descriptive terms like “articular fracture,” which is a break in the bone that extends into the smooth, cartilage-covered surface of the joint. This injury is of particular concern because it disrupts the smooth gliding mechanism, often leading to post-traumatic arthritis. Furthermore, conditions like juvenile idiopathic arthritis are categorized using terms such as oligo-articular, affecting four or fewer joints, or polyarticular, affecting five or more joints.