Manual of physiology for students and practitioners / by H. Willoughby Lyle.

  • Lyle, H. Willoughby.
Date:
1911
Catalogue details

Licence: In copyright

Credit: Manual of physiology for students and practitioners / by H. Willoughby Lyle. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    globin. In the higher types the oxy-hoemoglobiii is con- tained in the coloured blood corpuscles; in some of the lower types, such as the worms, it is dissolved in the blood plasma. Inorganic Salts, which, as has been already stated, are so essential for the biotic or physiological activity of the cells, are supplied by way of the plasma and tissue fluid or lymph, those supplied being sodium chloride, potassium chloride, calcium salts, and phosphates, whereas those found in the cells are chiefly potassium and phosphatic ions, suggesting that the cell proteins have some selective action for particular ions. Though the inorganic ions are adsorbed to the cell proteins, yet it is quite possible that each ion is capable of exerting its own osmotic pressure. The Lipoids of the cell play an important part in preserving the life of the cell, since they have the power of combining with organic poisons and toxins, which enter the body usually through the alimentary canal, or by way of the skin through the lymph stream present. In this way the bioplasm of the cell is guarded from these toxic influences, which might other- wise cause the death of the cell. It will be shown later that some of the cells of the tissues and organs produce, and therefore contain, intracellular enzymes. In some instances the action of these bodies serves to explain some of the physiological processes which take place in the cells and tissues of the body {vide Tissue Enzymes, p. 58). Summing up, then, it may be said that the living cell exists in a periodically varying osmotic equilibrium with its surroundings, that, as the result of its biotic activity, oxidative changes must occur with the production of energy, heat, and waste products (katabolism or destructive meta- bolism). As the result of these changes, unless death is to take place and these processes brought to an end, con- structive metabolism, anabolism, or assimilation must be con- tinually occurring. These processes, therefore, which are continually going on, constitute metabolism; when meta- bolism comes to an end, life ceases to exist. The metabolic changes which have been described as occurring in a typical animal cell, the physiological unit, are characteristic of those which take place in the individual, the physiological whole. As the body is composed of various organs, a division of