American journal of physiology (1898) (14597615680)

Identifier: americanjourna13ameruoft (find matches)

Title: American journal of physiology

Year: 1898 (1890s)

Authors: American Physiological Society (1887- ) American Physiological Society (1887- ). Abstracts of papers presented at the fall meeting American Physiological Society (1887- ). Proceedings

Subjects: Physiology Physiology

Publisher: (Bethesda, Md., etc.) American Physiological Society (etc.)

Contributing Library: Gerstein - University of Toronto

Digitizing Sponsor: University of Toronto

Text Appearing Before Image:

enomena resulting from thegraduated increase of vein pressure. — If the pressure in the renal vein isincreased by raising the out-fiowtube to the desired height, it isfound that, as the vein pressure ismade to rise, the flow from the veinand from the ureter is diminished,whilst the oncometer shows an in-crease of volume. The curves offlow are not, however, parallel tothe pressure (see Fig. 8). It maybe remarked that vein pressures upto 40 cm. have a relatively smalleffect on the flow, and that between40 cm. and 80 cm. the flow fromboth vein and ureter is suddenly-diminished. The curve is verymuch the same whether i per centor 2.5 per cent sodium chloride solu-tion is used. 3. The effect of vein pressure onvein flow in artificial models. — Toexplain the peculiar curves, theflow from artificial models was in-vestigated. The results were asfollows (Fig. 9) : (a) When the vein pressure is in-creased in a simple, non-leakingmodel, the curve is indeed convex,but it is perfectly regular.

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Figure 8. — Effect of vein pressure.The curves of the different experi-ments are superimposed. Thestraight line drawn from 0 to 145cm. (the mean injection pressure)represents the increase of veinpressure (a fall in this line indica-,ting an increase of vein pressure,in the case of the vein and ureterflow). (b) When a leak is introduced into the system similar to that in 1 Ludwig : Cited from Henle and Meissners Berichte, 1863, pp. 323 to 328. Perf2ision Experimc^its 07i Excised Kidiieys. 263 the kidney^ the flow lessens relatively more, as the vein pressure isincreased, reproducing the kidney curve. (c) The phenomenon can be reproduced in a non-leaking system,and even more strikingly when the model is composed of elastic tubescapable of mutual compression, such as will be described later. Simi-lar curves were obtained with the artificial glomerulus (Fig. il).They could doubtless be reproduced also with the twisting valve tobe described later. 4. The cause of the vein flow curve. —

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1898

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