Volume 1

A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling.

  • Landois, L. (Leonard), 1837-1902. Lehrbuch der Physiologie des Menschen. English
Date:
1891
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Licence: Public Domain Mark

Credit: A text-book of human physiology : including histology and microscopical anatomy with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition with additions by William Stirling. Source: Wellcome Collection.

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    causes dilatation of the organ, wliicli condition runs parallel with the rise of the blood-pressure. Stimulation of a sensory nerve, e.g., the central end of the sciatic nerve, while causing an increase of the blood-pressure, makes the kidney shrink.] [In poisoning with strychnin, the kidney shrinks while the blood-pressure rises. Stimulation of the central or peripheral end of the splanchnics, divided at the diaphragm, causes contraction of the renal vessels of hotli sides; the former is a re- flex, the latter a direct effect. Stimulation of the peripheral end of one splanchnic sometimes affects both kidneys. Stimulation of the peripheral end of the renal nerves always causes a diminution in the volume of the kidney, so that Cohnheim and Roy inferred that, although there was evidence of the existence of yaso-motor and sensory nerves to the kidney, they found none of vaso-dilators. Each kidney acts independently of the other. Sudden compression of one renal artery has not the slightest efl'ect upon the blood-current of the other kidney. If a kidney be exposed in an animal, by making an incision in the lumbar region, on stimulating the medulla oblongata directly with electricity, we may observe the kidney itself becoming paler, the pallor appearing in a great many small spots on the surface of the organ, corresponding to the distribution of the interlobular arteries.] [Cohnheim showed that the chemical composition of the blood has a remark- able effect on the renal circulation, the kidney being very sensitive to such changes in the composition of the blood. Some substances (water and urea), when injected into the blood, cause the kidney first to shrink and then to expand, while sodic acetate dilates the kidney, even after all the renal nerves are divided—an operation which is very difficult indeed. Provided all the renal nerves be divided, these effects would indicate the existence of some local intra-renal vaso-motor mechanism governing the renal blood-vessels. The general blood-pressure is not thereby modified; nor need we wonder at this, as ligature of one renal artery does not increase the pressure in the aorta.] [Vaso-constrictor and vaso-dilator nerves to kidney.—Rose and Bradford, by enclosing the kidney of a dog in an oncometer-tube confirmed the view, that not only are the kidneys well supplied with vaso-constrictor fibres, but that they also receive vaso-dilator fibres. The vaso-COnstrictor fibres leave the spinal cord (dog) by the anterior roots of the spinal nerves as high as the 6th dorsal, and as. low as the 2nd lumbar, (or even 4th); but by stimulating the peripheral end of each nerve-root singly, and observing the effect on the volume of the kidney, it has been shown that the largest number pass out by the 11th, 12th, and 13th dorsal nerves. From the anterior roots they enter the corresponding ganglia of the sympathetic, they enter the solar plexus, and pass via the renal plexus into the kidney. Some apparently do not enter the splanchnic nerve. Vaso-constrictor nerves are best excited by rapid electrical stimulation.] [Vaso-dilator fibres.—It is a peculiarity of vaso-dilator fibres that they are best excited by sloiv rhythmical stimulation (§ 372) (2-5 shocks per sec), and if the peripheral end of the anterior roots of certain of these nerves be stimulated the kidney dilates, showing that these nerves contain vaso-dilator as well as vaso-con- strictor fibres and the vaso-dilators seems to take the same course as the constric- tors, being most abundant in the 11th, 12th, and 13th dorsal nerves.] [The reciprocal relation between the skin and the kidneys is known to every one. On a cold day, when the skin is pallid, owing to contraction of the cutaneous vessels, the amount of urine secreted is great, and conversely, in summer less urine is passed than in winter. Washing the skin of a dog for two minutes with ice- cold water causes a great contraction of the kidney.] The perfusion of blood through a living excised kidney, ^.6'., a surviving kidney, is materially influenced by the substances mixed with the blood perfused. This effect may in part be due to the action of these chemical ingredients upon the
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