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Bone marrow

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Bone marrow is soft tissue found mainly inside the long bones, vertebrae, and pelvic bones of the body. It is made up of red marrow, which produces red and white blood cells and platelets, and yellow marrow, which contains fat and connective tissue.

People are born with only red bone marrow. As a person matures, the red marrow in many of the bones is replaced by yellow marrow. By adulthood, only about half of the bone marrow is red. Red bone marrow is found mostly in the ribs, breastbone, shoulder blades, collarbones, hip bones, skull, and spine.

Current as of: September 25, 2023

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: September 25, 2023

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.