chp:]\iical pathology 



CHAPTER I 



INTRODUCTION 



THE CHEMISTRY AND PHYSICS OF THE CELL 



Since Virchow founded modem pathology the unit of all anatomical 

 considerations of disease has been the cell, and in physiology the same 

 unit has been found equally useful. When either physiological or 

 pathological processes are studied from a chemical standpoint, the 

 cell is still found occupying nearly as fundamental a position, for 

 we can seldom go back to molecules and atoms in investigating 

 biological problems. Although we know that within each cell are 

 many different chemical substances, and that numerous different 

 enzj^mes and other agencies are exerting their influences upon them, 

 yet we find that the reactions are all profoundly affected by the 

 environment in which they occur, and it is the stracture of the cell 

 that determines the environment of its chemical constituents. All 

 chemical reactions are modified by physical influences, and an enzyme 

 may have quite a different effect upon a substance when it acts in a 

 test-tube from wliat it will have when in a living cell, whose struc- 

 ture permits the diffusion of one substance while preventing that of 

 another, and where countless other substances and enzymes may 

 participate in the changes. The cell is the structural unit of the liv- 

 ing organism, and as by its physical properties it modifies chemical 

 processes, so it becomes practically the unit in physiological and 

 pathological chemistry. All consideration of the chemistry of disease 

 must thus refer back to the chemistry and physics of the normal cell, 

 and on this account a brief resume of these subjects may serve as a 

 fitting introduction to the strictly pathological matters to follow.^ 



As a])plied to the animal tissues, the tenn "cell" is entirely a mis- 

 nomer, for it describes accurately only such forms of "cells" as are 



1 Of necessity, only so much of the vorv extensive literature on coll structure 

 and cell chemistry can be considered as will have direct bearing \ipon tiie subject 

 matter to follow, referring tlie reader for more detailed information to sucli works 

 as Wilson's "The Cell in Development and Inlioritance"; Mann's "Physioloirical 

 Histoloffy"'; Hammarsten's "Physiolofrical Cliemistry": Gurwitscli's "Morplioloeie 

 imd Biolo.srie der Zelle"; Hober's "Pliysikalisclie Cbemie der Zelle luid der 

 Clewebe"; Hamburojer's "Osmotischer Druck und Tonenlehre"; Loeb's "nviiamics 

 of Living Matter"; Oppenheimer's "ITandbuch der Biochemie"; and Botta-'zi, 

 "Handbuch der vergl. Pliysiologie," Vol. T, for general discussion, and to the most 

 important monographs for treatment of special points. 

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