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

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.

571/602 page 531

$and partly as pyrogallol, pyrokatechin, and other substances which turn brown when alkaline urine is exposed to the air.] Taurin and sarcosin unite with sulphaminic acid. When bronio- phenol is given, it unites with mercapturic acid, a body nearly related to cystin (§ 268). 7. Tannic acid, C14H10O9, takes up and is decomposed into two molecules of gallic acid --= 2(C,UM. 8. The iodates of potash and soda are reduced to iodides ; malic acid (C4H6O5) partly to succinic acitl (C4H6O4) ; indigo-blue (CjeHioNgOg) takes up hydrogen and becomes indigo-white (C.eH.oN^O,). 9. Some substances do not pass into the urine at all, e.g., oils, insoluble metallic salts and metals. 276. INFLUENCE OF NERVES AND OTHER CONDITIONS.—At present we are acquainted merely Avith the influence of the vaso-motor nerves on the circulation through the renal vessels. Uach kidney seems to be supplied with vaso- motor nerves, which spring from both halves of tlie spinal cord [Nicolaides). As a general rule, dilatation of the branches of tile renal artery, chiefly the vasa afferentia, must raise the pressure within the glomeruli, and thus increase the amount of water filtered through them. The more the dilatation is confined to the area of the renal artery alone, the greater is the amount of the urine. In the dog, the lower dorsal nerves contain the most vaso-motor nerves—both vaso-constrictor and vaso-dilator (p. 534)—for the kidney {Bradford). [As yet we know the nervous system influences the secretion of urine only in so far as it modifies the pressure and velocity of the blood-current in the kidney. We have no satisfactory evidence of the existence of direct secretory nerves in the kidney.] 1. Renal Plexus and its Centre.—Section of the nerves of the renal plexus— the nerves around the renal artery—generally causes a considerable increase in the secretion of urine, hydruria or polyuria; sometimes, on account of the great rise of the pressure within the glomeruli, albumin passes into the urine, and there may be rupture of the vessels of the glomeruli, leading to the passage of blood into the urine. The nerve-centre for the renal nerves lies in the floor of the fourth ventricle, in front of the origin of the vagus. Injury to this part of the floor of the fourth ventricle, e.g., by puncture (piqCire), may increase the amount of urine (diabetes insipidus), which is sometimes accompanied by the simultaneous appear- ance of albumin and blood in the urine {GL Berriard). Section of the parts which lie directly in the course of these fibres, as they pass from their centre to the kidney, l^roduces the same effects. Close to this centre in the medulla lies the centre for the vaso-motor nerves of the liver, whose injury causes diabetes mellitus (§ 175). Eckhard found that stimulation of the vermiform process of the cerebellum produced hydruria. In man, stimulation of these parts by tumours or inflammation, &c., produces similar results. 2. Paralysis of Limited Vascular Areas.—If, simultaneously with the paralysis of the nerves of the renal artery, the nerves of a neighbouring large vascular area be paralysed, necessarily the blood-pressure in the renal artery area will not be so high, as more blood flows into the other paralysed province. Under these circum- stances, there may be only a temporary, or, indeed, no increase of urine, provided the paralysed area be sufficiently large. There is a moderate increase of urine for several hours after section of the splanchnic nerve. This nerve contains the renal vaso-motor nerves (which, in part at least, leave the spinal cord at the first dorsal nerve and pass into the sympathetic nerve), but it also contains the vaso-motor nerves for the large area of the intestinal and abdominal viscera. Stimulation of this nerve has the opposite effect {CI. Bernard, Eckhard). [The polyuria thus produced is not so great as after section of the renal nerves, because the splanchnic supplies such a large vascular area, that much blood accumulates in that area, and also because all the renal nerves do not run in the splanchnics.] 3. Paralysis of Large Areas.—If, simultaneously with paralysis of the renal nerves, the great majority of the vaso-motor nerves of the body be paralysed [as by$