Galen: On the Natural Faculties by Galen

Chapter XIII

324 words  |  Chapter 43

Expulsion takes place through the same channel as attraction (_e.g._, in stomach, gall-bladder, uterus). Similarly the delivery (_anadosis_) of nutriment to the liver from the food-canal _viâ_ the mesenteric veins may have its direction reversed. Continuous give-and-take between different parts of the body; superior strength of certain parts is natural, of others acquired. When liver contains abundant food and stomach depleted, latter may draw on former; this occurs when animal can get nothing to eat, and so prevents starvation. Similarly, when one part becomes over-distended, it tends to deposit its excess in some weaker part near it; this passes it on to some still weaker part, which cannot get rid of it; hence _deposits_ of various kinds. Further instances of reversal of the normal direction of anadosis from the food canal through the veins. Such reversal of functions would in any case be expected _a priori_. In the vomiting of intestinal obstruction, matter may be carried backwards all the way from the intestine to the mouth; not surprising, therefore, that, under certain circumstances, food-material might be driven right back from the skin-surface to the alimentary canal (_e.g._ in excessive chilling of surface); not much needed to determine this reversal of direction. Action of purgative drugs upon terminals of veins; one part draws from another until whole body participates; similarly in intestinal obstruction, each part passes on the irritating substance to its weaker neighbour. Reversal of direction of flow occurs not merely on occasion but also constantly (as in arteries, lungs, heart, etc.). The various stages of normal nutrition described. Why the stomach sometimes draws back the nutriment it had passed on to portal veins and liver. A similar ebb and flow in relation to the spleen. Comparison of the parts of the body to a lot of animals at a feast. The valves of the heart are a provision of Nature to prevent this otherwise inevitable regurgitation, though even they are not quite efficient.