On the Passage of Sodium Iodide from the Blood to the Lymph, with some Remarks on the Theory of Lymph Formation
Journal of Physiology
From the Physiological Imntitute, Breslau.) FOR a long time the formation of the lymph was regarded as a simple process of mechanical filtration out of the blood plasma into the lymph spaces surrounding the capillaries. In his paper " Versuche und Fragen zur Lehre der Lympbbildung'," Heidenhain first pointed out that if the demands of various organs for specific substances are considered in connection with the amount of lymph actually formed in the body, we arrive at results which a theory of
... which a theory of simple filtration fails to explain. Thus he showed that on this theory, the CaO in the milk excreted daily by a cow would require a daily formation of about 236 litres of lymph in the mammary gland alone, an amount which is entirely out of the question. A plausible explanation of this and other similar facts is given by diffusion, the substance required by each tissue diffusing from the blood to the lymph; from which it is taken by the tissue, and so its tension in the lymph is reduced practically to zero. According to this view, every organ might, as Heidenhain suggests, be provided with the required blood constituents in somewhat the same way as it is with oxygen. In his investigations Heidenhain sought to determine whether such an explanation, plausible and possible as it seems, stands in accord with the facts of experiment. His observations on the passage of dissolved substances-sugar and sodium chloride, for example-from the blood to the lymph revealed facts which seemed to contradict a simple physical theory of lymph formation, and suggested that other 1 R. Heidenhain. Pfiuger's Archiv, XLIX. 1. 1891.