nivelpään

Nivelpää, or articular head, is the rounded end of a bone that forms part of a synovial joint. It is typically covered by articular cartilage and sits at the end of a bone, often near a constricted region called the neck. The articular head articulates with a complementary surface on the adjacent bone, such as a socket, fossa, or groove, enabling joint movement while distributing load.

An articular head is usually part of the bone’s epiphysis and participates in various types of joints, including ball-and-socket, hinge, and pivot joints. In ball-and-socket joints, for example, the head forms a sphere that fits into a corresponding socket, as seen with the femoral head in the hip and the humeral head in the shoulder. In other joints, the head may articulate with a shallower surface, aiding different ranges of motion. The shape of the head and the depth of the partner surface influence the joint’s mobility and stability.

The joint capsule, ligaments, and the synovial membrane with fluid surround the articular head, reducing friction and supplying nutrients to the cartilage. The integrity of the cartilage covering the head is crucial for smooth articulation; damage can lead to pain, restricted movement, and conditions such as osteoarthritis. Clinically, fractures or dislocations involving the articular head can have significant implications for joint function and long-term joint health.

In Finnish anatomy, nivelpää refers to this concept of the articular head found at the ends of bones that participate in synovial joints. Examples include the femoral head, humeral head, and radial head.