2 Basic Types of Bone Marrow Red (active): containing many stem cells and erythrocyte precursor cells. Yellow (less active): rich in adipocytes, few differentiating blood cells. can be transformed into red bone marrow by chronic hemorrhage or hypoxia.

Red Bone Marrow Found in sternum, vertebrae, ribs, clavicles, pelvis, long bones, skull.

Bone Marrow Functions Production of blood cells. erythrocytes, granulocytes, monocytes, and platelets released into circulation. lymphocytes require additional maturing. Destruction of old erythrocytes. carried out by macrophages in spleen, liver and bone marrow. Storing Fe from breakdown of hemoglobin. stored in macrophages and erythroblasts.

Yellow Bone Marrow Adipocytes, macrophages, mesenchyme, reticular cells. Serves as storage area for nutrients (fat) and reserve hematopoietic tissue.

Bone Marrow