CHAPTER 17 



Histological Changes after Irradiation 



William Bloom 



Department of Anatomy and Institute of Radiobiology and Biophysics, 



The University of Chicago 



and Margaret A. Bloom 



Chicago 



Introduction. Visible changes in cells: Cell membrane — Organelles — Interphase 

 nucleus — Dividing cells. Changes in tissues. Bone marrow. Lymphatic organs. 

 Thymus. Spleen. Bone. Cartilage. Male generative system. Female generative 

 system. Skin: Epithelium — Derma. Epidermal derivatives: Hair — Nails — Skin glands 

 — Mammary gland. Gastrointestinal system: Mouth, nasopharynx, and esophagus— 

 Stomach and intestines — Salivary glands — Liver — Gall bladder and biliary passages — 

 Pancreas. Urinary system: Kidney — Urinary bladder. Respiratory system. Nervous 

 system. Eye. Endocrine glands: Adrenal — Hypophysis — Thyroid — Parathyroid. Dis- 

 cussion. References. 



INTRODUCTION 



Within the first ten to fifteen years after their discovery, it was shown 

 that ionizing radiations, in amounts we recognize today as under 1500 r, 

 would produce marked degenerative changes in the skin and its append- 

 ages, parts of the gastrointestinal tract, the blood-cell-forming organs 

 (and thus in the blood), the gonads, conjunctiva and lens, bone, and 

 cartilage. It was also found that the skin might become ulcerated and 

 even cancerous. Moreover, it was learned that irradiation could destroy 

 some cancers and could produce embryological monsters. In the years 

 which have elapsed since then much knowledge has been added, but 

 much more is required before the visible effects of radiation on cells can 

 be presented in a complete and systematic fashion. 



Advances have been retarded by a number of factors. One of these is 

 our inability to evaluate dosages in the older reports before the introduc- 

 tion of the roentgen. Another is the difficulty of comparing the effects on 

 a particular organ of total-body irradiation with local irradiation of that 

 organ, since systematic studies on this theme are lacking. Further 

 variables which must be taken into account are the time-intensity factor 

 for a given dosage and, closely related to this variable, whether the radia- 



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