|MadSci Network: Anatomy|
The bones that produce white (and red) blood cells consist of two main layers, along with the covering layer (the periosteum). The inside spongy bone produces the blood cells. The outside compact bone makes the bone strong to support the muscles and weight of the body.
The compact bone layer features a number of foramina (openings) which allow the nutrient vessel(s) to tunnel through to reach the marrow cavity and spongy bone tissue within. Most bones have one main nutrient vessel which, by branching into a web of arterioles within the bone, feeds them, though the femur has two such nutrient blood vessels. The bone has one foramen for the entrance of each nutrient vessel, and foramina at the extremities for the produced blood to pass out of the bone.
The Haversian lamellae are layers of bone formed during the development of the bone which contain the Haversian canals. These canals house the blood vessels, lymph vessels, nerves, and marrow of the bone.
The Volkmann's vessels are located within the Haversian canals in the Haversian lamellae. These vessels carry the nutrients which nourish the bone tissue and carry newly generated blood cells and lymphocytes from the marrow to the bloodstream.
For more information, see www.sirinet.net/~jgjo hnso/skeleton.html
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