What lets a joint move so freely? The answer is a cavity, a space filled with fluid, between the bone ends. The ends are capped with slick cartilage. A capsule wraps it all. Tap each part.
Articular cartilage
Synovial jointtap a part
The parts
📷 Reference image
A real labeled figure to compare with the interactive above.
Structure of a Synovial Joint — OpenStax, CC BY 3.0 (via Wikimedia Commons)
