Basic Anatomy and Histology of the Lung

All studies of toxic effects must compare normal conditions with those existing after contact with the toxin. If the effects to be studied involve alterations of gross, microscopic or ultramicroscopic structures, then a knowledge of normality at each of these levels is essential. This understanding is equally true for every organ of the body from the skin to the bones. Our interest today is in the pulmonary effects of phosgene; consequently, this discussion of basic morphology will be directed entirely at the lower respiratory tract. While most of the research to be presented in subsequent papers will relate to experimental studies in animals of various species, all are probably intended to have relevance to human responses to contact with phosgene. This discussion, therefore, will be concerned with the human lung and with examples of two animal species, rats and dogs. Since any single author can do relatively little of the vast range of studies necessary to establish normal morphology, this discussion is necessarily derived largely from the literature. Rather than present copies of illustrations and charts, which would require extensive copyright negotiations, and many of which would lose detail in reproduction, its seems best to refer the reader to the original publications. Most of these are readily available in medical libraries. 1. PRATT, P.C. and KLUGH, G.A. , A Technique for the Study of Ventilatory Capacity, Compliance and Residual Volume of Excised Lungs for Fixation, Drying and Serial Sectioning in the Inflated State, Amer. Rev. Resp. Dis. , 83: 690, 1961. 2. HEARD, B.E. , ESTERLY, J.R. and WOOTLIFF, J.S. , A Modified Apparatus for Fixing Lungs to Study the Pathology of Emphasema, Amer. Rev. Resp. Dis. , 95: 311, 1967. 3. MATSUBA, K. and THURLBECK, W.M. , Disease of the Small Airways in Chronic Bronchitis, Amer. Rev. Resp. Dis. , 107: 552, 1973. 4. STAUB, N.C. , Relation Between Morphological and Physiological Events in the Lung Studied by Rapid Freezing, J. Appl. Physiol. , 17: 381, 1962. 5. STAUB, N.C. NAGANO, H. and PEARCHE, M.L. , Pulmonary Edema in Dogs, Especially the Sequence of Fluid Accumulation in Lungs, J. Appl. Physiol. , 22: 227, 1967. 6. HEBEL, R. and STROMBERG, M.W. , Anatomy of the Laboratory Rat, Williams and Wilkins Co., p. 55, Baltimore, 1976. 7. PARK, J.F. , CLARK, W.J. and BAIR, W.J., in The Beagle as an Experimental Animal, edited by A.C. Anderson, p. 285, The Iowa State University Press, Ames, Iowa, 1970. 8. KRAHL, V.E. , Anatomy of the Human Lung, in Handbook of Physiology, Sec. 3, Respiration, Vol. I, edited by H. Rahn, and W.O. Fenn, p. 213, Amer. Physiol. Soc. , Washington, D.C., 1964. 9. BREEZE, R.G. and WEELDON, E.B. , The Cells of the Pulmonary Airways, Amer. Rev. Resp. Dis. , 116: 705, 1977. 10. KUHN, C. , III, Ultrastructure and Cellular Function in the Distal Lung, in The Lung, Structure, Function and Disease, edited by W.M. Thurlbeck, p. 1, Williams and Wilkins Co., Baltimore, 1979. 12. WEIBEL, E.R. , Morphometrics of the Lung, in Handbook of Physiology, Sec. 3, Respiration, Vol. I, edited by H. Rahn, and W.O. Fenn, p. 285, Amer. Physiol. Soc. , Washington, D.C., 1964. 13. WEIBEL E.R. , Steriological Methods, Vol. 1, Academic Press, London, 1979. 14. PRATT, P.C. , Lung Dust Content and Response in Guinea Pigs Inhaling Three Forms of Silica. Arch Envron Health 38: 197-204, 1983. 15. PINKERTON, K.E. , BARRY, B.E. , O'NEIL, J.J., RAUB, J.A. , PRATT, P.C. and CRAPO, J.D. , Morphologic Changes in the Lung During the Lifespan of Fischer 344 Rats, Amer. J. Anatomy, 164: 155, 1982.