How would the function of synovial joints be changed if they lacked joint cavities and the bones were united instead? Explain.

In the absence of joint spaces (cavities) and bones fused together, body movements would be null or reduced.

Explanation:

The joints are the spaces where two bones meet, with cartilaginous tissue - articular cartilage and ligaments - to allow elasticity and body movements.

The articular cavities are spaces where bone union occurs through ligaments, surrounded by an articular capsule and upholstered inside by a membrane that produces liquid, the membrane and synovial fluid, respectively. These joints are usually found in the mobile body segments.

If the joint cavities did not exist, and the joints occurred between bone and bone, body mobility would not be possible. In the case of the skull bones, they do not have joint space, since their function is the protection of the organs of the central nervous system, not movement.

Learn more:

Types of structural and functional joints link