Bone Marrow: Red and Yellow
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
Red bone marrow produces blood cells inside spongy bone cavities, while yellow bone marrow stores fat and gradually replaces red marrow in many bones with age.
Show
An adult's red marrow concentrates in flat bones like the sternum, while long-bone shafts hold mostly yellow marrow.
Watch for
Yellow marrow can revert to blood-cell production under severe demand — the two types are not fixed permanently.