Selected monographs.

Date:: 1888

Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs. Source: Wellcome Collection.

70/440 (page 54)

them, are in all respects similar to those which obtain when the temperature is raised by simple exposure to heat. Can there be any doubt that the kidneys participate in the general increase of temperature caused by muscular exertion, and can we possibly conceive that, notwithstanding the fluxion to these organs and the rise in temperature, the renal vessels should be diminished in calibre and receive a smaller supply of blood ? We must reject all previous experience before we can entertain such a suggestion. As far as regards, however, the tetanic irritation of nerve-trunks by means of electricity, we must allow that Heidenhain is correct in the objection he raises, to the conclusions drawn from these experiments, with regard to the activity of glands in muscular exertion, his belief being that the abdo- minal vessels probably become contracted in a reflex manner, just as occurs when the sensory nerves are violently irritated (56). The diminution in the quantity of urine and its concentrated condition, which follow muscular exertion, are brought forward by Euneberg (57) as proofs that the pressure is diminished in the renal vessels. We are exempted from any controversy with regard to this view, inasmuch as we have given an obvious and very simple reason why the urine becomes less watery after muscular exertion. We may in the last place specify the process of digestion, and certain poisons, as factors by which the arterial blood pressure can be more or less positively raised, or is perhaps regularly increased. With regard to the former of these, certainly I do not know of any experiments in which the pressure has been directly measured, but Zadek in his re- searches, has indirectly observed that the pressure is increased. Besides this, however, the existence of such increase might, with some probability, be inferred from the fact long since observed by Vierordt and Aberle that the size of the arteries is increased after taking food (58); and also, that during diges- tion certain changes take place in the circulation which, at least faintly resemble the condition which follows muscular exer- tion and exposure to heat, and have therefore been designated as digestion-fever. It is true that this increase of pressure does not appear to be very considerable as a general rule ;