Fatma Faiez Mohamed, Graduate Student (Franceschi Laboratory), Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry
All of the cells that make up the blood are generated in the bone marrow, a specialized space in the core of some of our bones (e.g., the long bones of the leg, the breastbone and hip). Within this marrow space, progenitor cells (blood stem cells) constantly give rise to red cells (which carry oxygen to our tissues), white cells (which function in immunity) and platelets (which control blood clotting) that enter the blood stream. The bone marrow is an amazing cell production factory, generating approximately 500 billion cells per day! This is an image of part of a leg bone from a two week-old mouse. The sample has been stained to show bone (red) and cartilage (green) that surrounds the massive number of marrow cells (pale yellow). It is also possible to discern many newly born red blood cells (red/pinkish) that have entered a few vessels that course within the marrow.