DISEASES OF THE SUPRARENAL GLANDS EVOLUTION, ANATOMY, AND PHYSIOLOGY Our knowledge of the evolution of the suprarenal glands is still deficient. Although the opinion prevails that the cortical substance proceeds from the pronephros, while the medullary substance is genet ically connected with the sympathetic nervous system, there are still authors who deny any evolutionary connection between the pro nephros and the genito-urinary system. They support their opinion by the fact that among other things, the suprarenal glands may be preserved even if the urinary apparatus is completely lacking, and that, these organs do not participate in the congenital change of situation of the kidney. There is a time in life when the suprarenal gland is larger than the kidney. In adults the relation of the suprarenal to the kidney is as 1: 28; in the newborn it is as 1:3.
A section through tlac suprarenal gland shows the division into two portions, which are distinguished by their color: the yellowish and radially striped being the cortical substance, and the grayish red and spongy being the medullary substance. The latter consists of cells which will turn intensely yellow or brown when treated with chromic acid (chromatin cells), as shown by Kohn, of Prague,—a fact of the greatest importance since it was instrumental in showing the wide extension of these cells, which compose the medullary substance, throughout the human organism, and especially of the newborn. The latter—as shown by the examinations of Kohn, Zuckerkandl, and Wieset—is extraordinarily rich in chromatin tissue, which has evidently the same physiological significance as the medullary substance of the suprarenal glands. Zuckerkandl found, beside the inferior Inesenterie
artery, in the embryo and in the newborn, an oblong, oval formation of which the most essential elements are chromatin cells (by-bodies of the sympathetic). Its structure corresponds to the medulla of the suprarenal glands, but it does not contain ganglionic cells. Wiese] discovered a surprising abundance of chromatin tissue in the retro peritoneal space of the newborn, in the codiac plexus, and near the exit of the inferior mesenteric artery. (Part of this tissue will later retrograde to the sympathetic.) The testicles of about 75.5 per cent. of thc newborn contain, according to Wiesel, chroinatin tissue.
The fact that the whole mass of the chromatin system represents a complex of cells of which the function is a unit, promises to become of importance in pathology, because physiological and chemical inves tigation have shown that it is only- from the medullary portion of the suprarenals, and from other chromatin tissues, that there can be ob tained the substance which, when introduced into the animal body (even in minute quantity, fraction of a milligram), can raise the blood pressure enormously. This is the so-called adrenalin which was crys talized out by Takamine, and it seems as if we shall soon ascertain its constitution and synthesis. This body cannot be developed front the cortex of the suprarenal gland, which is of greater importance to life than the medullary substance, as has been shown by experiment. The importance of the cortical substance in the normal processes of life is said to be its antitoxic action, but this is still hypothetical.