radguide

21 Radiation for Radionuclide Users the degree of cell differentiation. Table 1 presents a list of cells which generally follow this principle. List of Cells in Order of Decreasing Radiosensitivity Very radiosensitive lymphocytes (cellular elements of lymph) erythroblasts (cells of red marrow that synthesize hemoglobin and that are intermediate in the initial stage of red blood cell formation) spermatogonia (primitive male germ cells) basal cells (innermost cells of the deeper epidermis of the skin) endothelial cells (thin, flattened cells that line the internal body cavities) Moderately radiosensitive osteoblasts (bone forming cells) granulocytes (polymorphonuclear white blood cells with granule- containing cytoplasm) osteocytes (cells characteristic of adult bone and isolated in small cavities of the bone substance) sperm (mature male germ cell) erthrocytes (red blood cells) fibroblasts (cells that produce the fibrous connective tissue) Relatively radioresistant fibrocytes (fibrous connective tissue cells) chondrocytes (cartilage tissue cells) muscle cells (primitive male germ cells) nerve cells (thin, flattened cells that line the internal body cavities) The considerable variation in the radiosensitivities of various tissues is due, in part, to the differences in the sensitivities of the cells that compose the tissues. Also important in determining tissue sensitivity are such factors as the site of nourishment of the cell, interactions