Red is found in the open areas of spongy bone and functions in blood cell production. Yellow consists mostly of fat cells and is found in long bones. Classifications of Joints Basically, you can divide joints into 2 categories based upon their function and make-up. The union of the bony elements are surrounded by an articular capsule enclosing a cavity lined by synovial membrane. A capillary network in the synovial membrane secretes synovial fluid and nutrients to nourish and provide lubrication for the joint.
Ligaments provide strength and protection to synovial joints.
Examples include the elbow, knee and IP joints of the fingers. 1st MCP joint. Examples include the hip and shoulder joints. A disruption of bone caused by mechanical forces applied either directly to the bone or transmitted along the shaft of the bone. The extent of the fracture means it is either complete which crosses the entire bone or incomplete, which does not.