Which statement is true about synovial joints?

• A. They are immovable
• B. They are diarthrotic
• C. They are fibrous
• D. They are synarthrotic

Answer: (B)

Freely movable joints are diarthrotic. Synovial joints achieve their movement with a synovial cavity, lubricating fluid, articular cartilage, and a fibrous capsule reinforced by ligaments, all working together to allow a wide range of motion while minimizing friction. This combination is the defining feature that makes them diarthrotic, the category for joints that are actively movable, like the shoulder, elbow, or knee.

They aren’t immovable, which would describe synarthrotic joints such as skull sutures, nor are they fibrous joints, which are bound by dense connective tissue and typically have little or no movement. Describing synovial joints as synarthrotic or fibrous would misclassify their functional nature.