What does the medullary (marrow) cavity contain?

The medullary (marrow) cavity is primarily responsible for housing yellow, fatty marrow. This kind of marrow serves as an important energy reserve and is involved in the storage of fats. As individuals age, the ratio of yellow marrow increases, while red marrow, which is responsible for blood cell production, diminishes in certain bones.

While cartilage tissue is indeed found in other areas of the body, it is not located within the medullary cavity. Furthermore, while nerves and blood vessels do play a significant role in the surrounding structures and overall bone health, they do not fill the cavity itself. Red blood cells, on the other hand, are produced in the red marrow found in certain bones, but the primary content of the medullary cavity in adults is yellow marrow.