Muscle tissue, radiation sensitivity

In the mammalian (including the human) organism, the most sensitive cells are the circulating small lymphocytes and the internal layer of vessels, the endothelial cells. Tissues in decreasing order of radiation sensitivities are the lymphatic tissue, bone marrow, epithelia of stomach and intestines, the gonad cells, the basal layer of skin, the glandular tissues, liver, the connective tissue, muscle, and the nervous tissue. 

Tissues vary in their sensitivity to radiation, the most sensitive being the lymphocytes of the blood they respond to excess radiation by a drop in their number within a couple of days, followed by a fall in other blood cells. Next in sensihvity are the cells of the gonads, the bowel lining, the skin, lung, liver, kidney, muscle and nerves. 

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