Final answer:
A freely movable synovial joint is known as a diarthrosis. It features a synovial cavity filled with synovial fluid, allowing substantial movement while being stabilized by an articular capsule. Examples include the knees, elbows, and shoulders.
Step-by-step explanation:
Because it is a freely movable joint, a synovial joint is also called a diarthrosis joint. Synovial joints are characterized by the space between the bones known as a synovial or joint cavity, which is filled with synovial fluid. This fluid serves to lubricate the joint, reducing friction and allowing for a greater range of motion. The surfaces of the bones are not directly connected, instead, the joint is supported by an articular capsule composed of connective tissue which aids in movement and provides stability.
Synovial joints, such as the knees, elbows, and shoulders, are capable of extensive movement, making them integral to our daily activities that involve mobility. These joints are categorized as uniaxial, biaxial, or multiaxial, based on the number of axes along which they can move, corresponding to movements in the anatomical planes of the body.