Called also arthrodial joint and plane joint. Synovial joint A joint in which 1 the opposing bony surfaces are covered with a layer of hyaline cartilage or fibrocartilage, 2 there is a joint cavity containing synovial fluid, lined with synovial membrane and reinforced by a fibrous capsule and ligaments, and 3 there is some degree of free movement possible. Usually only one or a few joints are affected, such as the big toe, knee, or ankle. Chapter Review Synovial joints are the most common type of joints in the body. Based only on their shape, plane joints can allow multiple movements, including rotation. Indirect joint support is provided by the muscles and their tendons that act across a joint.
It is a connective tissue sac that surrounds a muscle tendon at places where the tendon crosses a joint. Joint replacement is a very invasive procedure, so other treatments are always tried before surgery. This fluid-filled space is the site at which the articulating surfaces of the bones contact each other. In this case, the articulation area has a more oval elliptical shape. The second movement is a side-to-side movement, which allows you to spread your fingers apart and bring them together, or to move your hand in a medial-going or lateral-going direction. Lesson Summary Our bodies contain six types of synovial joints. The bone rotates within this ring.
This will cause pain, swelling, or tenderness of the bursa and surrounding area, and may also result in joint stiffness. Numerous vessels from this plexus pierce the fibrous capsule and form a rich vascular plexus in the deeper part of the synovial membrane. A diet with excessive fructose has been implicated in raising the chances of a susceptible individual developing gout. Gout is a form of arthritis that results from the deposition of uric acid crystals within a body joint. Plane Synovial Joints of Carpus Hinge joints: In these joints the articular surfaces are pulley shaped. Thus plane joints can be functionally classified as a multiaxial joint.
. However, unlike at a cartilaginous joint, the articular cartilages of each bone are not continuous with each other. Otherwise in most of the joints there role is negligible. The different types of synovial joints are the ball-and-socket joint shoulder joint , hinge joint knee , pivot joint atlantoaxial joint, between C1 and C2 vertebrae of the neck , condyloid joint radiocarpal joint of the wrist , saddle joint first carpometacarpal joint, between the trapezium carpal bone and the first metacarpal bone, at the base of the thumb , and plane joint facet joints of vertebral column, between superior and inferior articular processes. Synovial Joints These joints are the most common, and are found in nearly all the limb joints. The changes which occur are irreversible and degenerative.
In addition, there are other ligaments outside the joint cavity that also support the integrity of joints. As the disease progresses, the articular cartilage is severely damaged or destroyed, resulting in joint deformation, loss of movement, and severe disability. Others have multiple degrees of freedom, but at the expense of greater risk of injury. Muscles and their tendons acting across a joint can also increase their contractile strength when needed, thus providing indirect support for the joint. Bursae reduce friction by separating the adjacent structures, preventing them from rubbing directly against each other. Repeated acute episodes of bursitis can result in a chronic condition. A second pivot joint is found at the proximal radioulnar joint.
To begin our investigation, let's focus on the pivot joints. With no known cure, treatments are aimed at alleviating symptoms. Examples include the prepatellar bursa located over the kneecap and the olecranon bursa at the tip of the elbow. It holds together the articulating bones and supports the underlying synovium. Ball-and-socket joints are classified functionally as multiaxial joints. The joint responds by increasing production of the lubricating synovial fluid, but this can lead to swelling of the joint cavity, causing pain and joint stiffness as the articular capsule is stretched.
Rotation at this joint allows you to turn your head from side to side. Both condyloid and saddle joints are functionally classified as biaxial joints. A large submuscular bursa, the trochanteric bursa, is found at the lateral hip, between the greater trochanter of the femur and the overlying gluteus maximus muscle. Next, let's focus on hinge joints, shown as letter B on the diagram. These may be located outside of the articular capsule extrinsic ligaments , incorporated or fused to the wall of the articular capsule intrinsic ligaments , or found inside of the articular capsule intracapsular ligaments. The ball-and-socket joint is by far the least stable and is the easiest to dislocate, while the plane joints are very stable.
A subcutaneous bursa is located between the skin and an underlying bone. The parts, which are always built in advance of the surgery, are sometimes custom made to produce the best possible fit for a patient. Friction between the bones is reduced by a thin layer of articular cartilage covering the surfaces of the bones, and by a lubricating synovial fluid, which is secreted by the synovial membrane. The bones of the joint articulate with each other within the joint cavity. This type of surgery involves replacing the articular surfaces of the bones with prosthesis artificial components. Hinge joints, such as at the elbow, knee, ankle, or interphalangeal joints between phalanx bones of the fingers and toes, allow only for bending and straightening of the joint.
This allows the two bones to fit together like a rider sitting on a saddle. The presence of a space called a synovial cavity between aticulating bones allows the joint to be movable. The motion at this type of joint is usually small and tightly constrained by surrounding ligaments. They are the most common and most movable type of in the body of a mammal. Exercise, anti-inflammatory and pain medications, various specific disease-modifying anti-rheumatic drugs, or surgery are used to treat rheumatoid arthritis.