Final answer:
Synovial joints are characterized by the presence of a synovial cavity, filled with lubricating synovial fluid that allows the bones to move smoothly. These joints are surrounded by an articular capsule and are stabilized by ligaments, and typically found in the knees, elbows, and shoulders.
Step-by-step explanation:
Synovial Joints and Their Cavities
Synovial joints, also known as movable joints, are a specialized type of joint present in the human body. Distinctively, these joints feature a synovial cavity, which is a space filled with synovial fluid that separates the articulating bones of the joint. The synovial fluid within this cavity serves as a lubricant, significantly reducing friction and enabling the bones to move smoothly against each other in various motions. The joint surfaces are covered with a layer of articular cartilage, a smooth tissue that also aids in movement and minimizes wear.
The entire assembly is encased by an articular capsule, composed of fibrous connective tissue. Not only does this capsule provide a secure enclosure for the joint, but it also facilitates the range of motion while preventing dislocations. Within this framework, ligaments may also be present, contributing additional support and stability to the joint. Synovial joints are known for their great mobility and can be found in areas such as the knees, elbows, and shoulders. However, it's noteworthy to mention that with increased mobility can come a decrease in joint stability.