Tags: Anatomical Structure.
In anatomy the endosteum (plural endostea) is a thin layer of connective tissue that lines the surface of the bony tissue that forms the medullary cavity of long bones. This endosteal surface is usually resorbed during long periods of malnutrition resulting in less cortical thickness. The outer surface of a bone is lined by a thin layer of connective tissue that is very similar in morphology and function to endosteum.