Editing Bone (section)

===Synthetic===
The cancellous part of bones contain [[bone marrow]]. Bone marrow produces blood cells in a process called [[hematopoiesis]].<ref>{{cite journal | vauthors = Fernández KS, de Alarcón PA | title = Development of the hematopoietic system and disorders of hematopoiesis that present during infancy and early childhood | journal = Pediatric Clinics of North America | volume = 60 | issue = 6 | pages = 1273–1289 | date = December 2013 | pmid = 24237971 | doi = 10.1016/j.pcl.2013.08.002 }}</ref> Blood cells that are created in bone marrow include [[red blood cell]]s, [[platelet]]s and [[white blood cell]]s.{{sfn|Young|2006|pp=60–61}} Progenitor cells such as the [[hematopoietic stem cell]] divide in a process called [[mitosis]] to produce precursor cells. These include precursors which eventually give rise to [[white blood cells]], and [[erythroblast]]s which give rise to red blood cells.{{sfn|Young|2006|p=60}} Unlike red and white blood cells, created by mitosis, platelets are shed from very large cells called [[megakaryocyte]]s.{{sfn|Young|2006|p=57}} This process of progressive differentiation occurs within the bone marrow. After the cells are matured, they enter the [[circulatory system|circulation]].{{sfn|Young|2006|p=46}} Every day, over 2.5 billion red blood cells and platelets, and 50–100 billion [[granulocyte]]s are produced in this way.{{sfn|Young|2006|p=58}}

As well as creating cells, bone marrow is also one of the major sites where defective or aged red blood cells are destroyed.{{sfn|Young|2006|p=58}}