Outlines of the clinical chemistry of urine / by C.A. Mac Munn.

  • Macmunn, Charles A., 1852-1911.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of the clinical chemistry of urine / by C.A. Mac Munn. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

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    Nerves.—The nerves of the kidney accompany the arteiy, and contain a number of ganglia. When the nerves are cut the blood-vessels of the kidney dilate, and when they are stimulated the blood-vessels contract. These nerves come from the renal plexus and the lesser splanchnic nerve, and contain filaments derived from the sympathetic and cerebro- spinal systems,* When the splanchnics are divided the vessels of the kidney generally dilate, and by irritation af the splanchnics they are caused to contract. It is supposed that the nervous centre for the renal arteries is situated— like the principal vaso-motor centre for the body—in the medulla; but there are reasons for supposing that there are other centres in the spinal cord and in the solar and mesen- teric plexuses.-f- When a puncture is made in the floor of the fourth ventricle the quantity of urine increases considerably, although it is at first diminished. Stimulation of the vaso- motor centre in the medulla, such as is produced by venous blood or certain drugs—for example, digitalis—causes the renal blood-vessels to contract, like those in other parts of the body. But if, under these circumstances, the renal nerves are divided, then the arteries dilate and the amount of urine is very much increased, its increase being caused not only by the dilatation of the renal vessels, but by the increased arterial tension in other parts of the body. The nitrites are said to paralyze the muscular fibres in the vasa afferentia,. while digitalis increases the arterial tension all over the body ; hence Lauder Brunton suggests that by combining spirit of nitrous ether (for example), which contains nitrite of ethyl, with digitalis, we should obtain a much freer flow of urine than if we give digitalis alone.;]: Theories of Secretion.—As I said above, two distinct processes take place in the kidney, namely (1) modified filtration and (2) a true secretion. Bowman maintained that * Quain's Anatomy, 9th ed., vol. ii., p. 659. t Lauder Brunton : Loc. cit. X Lauder Brunton: Practitioner, vol. xxxii., 1884. Cf. also Leech: Nitrite of Ethyl, Med. Chronicle, vol. ix., 1888, p. 177.