CHAPTER 15 



The Pathological Physiology of Radiation Injury 

 in the Mammal. II. Specific Aspects of the Physiology 



of Radiation Injury 



Harvey M. Patt and Austin M. Brues 



Division of Biological and Medical Research, Argonne National Laboratory, 



Lemont, III. 



Introduction. Blood and hema,topoiesis. Abnormal bleeding. Body fluids: Blood 

 and plasma volume — Lymph and tissue fluid — Constituents of plasma and lymph. 

 Cardiovascular system. Gastrointestinal tract. Liver. Kidney. Endocrines: Adrenal 

 — Thyroid — Pituitary. Nervous System. Miscellaneous tissues and organs. Metabo- 

 lism and tissue breakdown. Immunity and injection. Nonspecific physiological 

 stresses. Acute radiation syndrome. References. 



INTRODUCTION 



The physical and biological factors that influence the response to high 

 energy radiation have been considered in Chap. 14. We are concerned 

 here with the physiological aspects of irradiation of specific sites or of 

 the whole organism. In general, the development and course of injury 

 are similar whether ionization and excitation result from penetrating 

 external radiations or from internally deposited radioactive materials. 

 While biological effectiveness differs for the several radiation qualities, 

 it is difficult to discern by physiological or histological means whether 

 irradiation has been accomplished by slow or fast neutrons, X or 7 rays 

 when a median lethal dosage is employed. External /3 irradiation is dis- 

 tinguished by the superficial nature of the damage, and the results of 

 poisoning with internal emitters are modified by the organ distribution 

 and trajectory of the radiating particles. 



It is clear that no single change is peculiarly specific for radiation 

 injury. Since the ionizing energy is dissipated in a heterogeneous and 

 highly integrated system, many different effects may ensue, and not all 

 of these are a direct consequence of exposure. Thus, we must contend 

 not only with the physicochemical complexities of energy absorption, but 

 with the many ramifications of function in the organism seeking to retain 

 physiological balance. Although the early biochemical and cytological 

 effects probably bear a causal relation to the gross pathological physi- 



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