Synovial joints (or diarthroses, or diarthroidal joints) are the most common and most movable type of joints in the human body. As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones.
Structural and functional differences distinguish synovial joints from cartilaginous joints (synchondroses and symphyses) and fibrous joints (sutures, gomphoses, and syndesmoses). The main structural differences between synovial and fibrous joints is the existence of capsules surrounding the articulating surfaces of a synovial joint and the presence of lubricating synovial fluid within that capsule (synovial cavity).
Structure
- Articular capsule: The fibrous capsule is continuous with the periosteum of bone. It is also highly innervated but avascular (lacking blood and lymph vessels)
- Articular cartilage: lines the epiphyses of joint end of bone. Provides the loading and unloading mechanism to resist load and shock
- Synovial membrane: the inner layer of the fibrous articular capsule. The synovial membrane covers the lining of the synovial cavity where articular cartilage is absent.
