bone marrow

bone marrow

Fig 1. Bone marrow and the cells that develop from it. Image credit: Schneider Children's Hospital.

bone marrow

Fig 2. Cross-section through a bone showing bone marrow.

Bone marrow is the soft, fatty, vascular tissue that fills the cavities in large bones and and contains hematopoietic stem cells, from which develop erythrocytes (red blood cells), many leukocytes (white blood cells), and platelets. It is red or yellow in color. In new born babies, red bone marrow is present in all bones; during teen years, most is replaced by yellow marrow. The marrow used in bone marrow transplantation is red.


The bone marrow also contains mesenchymal stem cells that a number of cell types come from, including chondrocytes, which produce cartilage.


Sites of red bone marrow in adults
The sites of red bone marrow in adults: spine, sternum, pelvis, ribs, scapulae, clavicles, and skull bones.