The |marrow| (also called medullary) cavity is the region within the bone which houses the |marrow|, responsible for generation of |blood cells|. The |marrow| in newborns and children is generally red, turning yellow in adults in all bones with the exceptions of upper ends of the |humerus| and |femur| and in many of the flat bones of the |skull|, |vertebrae|, |ribs|, |sternum|, and hip. The red |marrow|, also known as myeloid tissue, produces all types of |blood cells| except for ~lymphocytes~ and monocytes (which are formed primarily in the |lymph nodes| and the |spleen|). ~Anemia~ is a disease in which the myeloid tissue cannot produce sufficient red |blood cells| (as when the body does not get enough of the mineral iron), with the chief symptom being chronic fatigue.
