Within a long bone, the portion of the diaphysis containing marrow. image
The space within a bone that contains the marrow.
Marrow cavity; central cavity in long bone.
The medullary cavity is the central cavity of bone shafts where yellow marrow (adipose tissue) is stored. Located in the main shaft of the bone (diaphysis), the medullary cavity has walls composed of compact bone and is lined with a thin, vascular membrane (endosteum).