What Is a Synovial Joint Definition

Synovial joints allow movement, but are also prone to arthritis. See how arthritis causes joint pain The surface of a synovia may be flat or covered with finger-shaped projections (villi) so that soft tissues can change shape as joint surfaces move towards each other. Just below the intima, most synovies have a dense network of small blood vessels that provide nutrients for the synovia and avascular cartilage. The joint with the greatest range of motion is the patella. At these joints, the rounded head of a bone (the ball) fits into the concave joint (cavity) of the adjacent bone (see Figure 9.4.3f). The hip joint and the glenohumeral joint (shoulder joint) are the only patellae in the body. At the hip joint, the head of the femur articulates with the acetabulum of the hip bone, and at the shoulder joint, the head of the humerus articulates with the glenoid cavity of the scapula. Watch this video to learn more about the symptoms and treatments for rheumatoid arthritis. What body system works in rheumatoid arthritis and what causes it? Synovial joints consist of five classes of tissues: bone, cartilage, synovial, synovial fluid, and traction tissue, which consists of tendons and ligaments. The synovial mucosa in the sheaths of the bursa and tendon, similar to that of the joints, is a slippery, non-adhesive surface that allows movement between tissue levels. The synovial tendon sheaths tendons only where they pass through narrow passages or the retina, such as in the palm of the hand, on the wrist and around the ankle.

Elsewhere, the tendon is in a bed of loose fibrous tissue. On a condyloid joint (ellipsoid joint), the shallow depression at the end of a bone with a rounded structure of one or more adjacent bones is articulated (see figure 9.4.3e). The ankle (metacarpophalangeal) joints of the hand between the distal end of a metacarpal bone and the proximal phalanx are condyloid joints. Another example is the radiocarpal joint of the wrist, between the shallow depression at the distal end of the radius bone and the rounded, whimsical, triquetrum-colored carpal bones. In this case, the joint area has a more oval (elliptical) shape. Functionally, condyloid joints are biaxial joints that allow two levels of movement. A movement is to bend and straighten the fingers or the front-back movements of the hand. The second movement is a lateral movement that allows you to spread your fingers apart and bring them closer together, or move your hand in a medial or lateral direction. The patellae are functionally classified as multiaxial joints. The femur and humerus can move in both the front-back and medial-lateral directions, and they can also rotate around their long axis. The flat pan formed by the glenoid cavity allows the shoulder joint to have a wide range of motion. In contrast, the deep alveoli of the acetabulum and the strong support bands of the hip joint serve to restrict the movements of the femur, reflecting the need for stability and load capacity at the hip.

Flat joint: The left shoulder and shoulder-to-shoulder joint and the correct ligaments of the shoulder blade. During a swivel joint, a rounded part of a bone is enclosed in a ring, which is formed partly by articulation with another bone and partly by a ligament (see figure 9.4.3a). The bone rotates inside this ring. Since the rotation rotates around a single axis, swivel joints are functionally classified as uniaxial osteoarthritis. An example of a pivoting joint is the atlantoaxial joint, located between the C1 (atlas) and C2 (axis) vertebrae. Here, the caves of the axis protruding upwards articulate with the inner appearance of the atlas, where it is held by a ribbon. Rotating on this joint allows you to rotate your head from side to side. A second swivel joint is located on the proximal radios solal joint. Here, the head of the ray is largely surrounded by a band that holds it in place because it articulates with the radial notch of the ulna. The rotation of the radius allows movements of the forearm.

In a flat joint (sliding joint), the articular surfaces of the bones are flat or slightly curved and about the same size, allowing the bones to slide against each other (see Figure 9.4.3d). Movement on this type of joint is usually small and is severely constrained by the surrounding ligaments. .

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