ABSTRACT
The blood cells as individual cells enter the blood from the hematopoietic organs and remain in the blood for limited periods of time before entering other tissues and/or dying. The hematopoietic tissues consist basically of a framework stroma of reticular cells and fibers in the meshes of which the hematopoietic processes take place. The radiation effects on organs of the hematopoietic system are in terms of the effects of single doses of whole-body irradiation, with added discussion as needed on the effects of localized irradiation of the organs where there may be differences involved. In normal active red bone marrow the network of stromal cells and fibers is loose, with larger meshes than that in lymphoid tissue, and fat cells are always present. The fragmentary literature on the effects of localized irradiation on lymph nodes and lymph vessels shows sharp differences of opinion, contradictions, and little definitive long-term study.
