Structure of Kidney 



345 



quickly expand into calyces which, embracing the tops of the pyramids, 

 collect the urine. (For ureter, see p. 349.) 



The function of the kidney is to get rid of the excess of water, with, 

 of course, certain excrementitious substances in solution ; it is thus 

 closely associated with the skin, with the mucous membrane of the 

 bowel, and to a certain extent with the lungs. When the diseased 

 kidney demands rest the skin and the bowels should be set to work 

 by diaphoretics and purgatives. 



When a patient with acute intestinal obstruction is constantly 

 vomiting there is little or no fluid for the kidney to drain off, and 

 suppression of urine is noted ; and when a man is perspiring profusely, 

 or is racked with diarrhoea or cholera, he passes hardly any urine. 

 That which comes away in such cases is laden with excrementitious 

 materials and is consequently of high specific gravity. 



Structure. The cortical part consists of branching and coiled 

 tubules, and of ramifications of blood-vessels, in which the bases of the 

 twelve or twenty pyramids of the medullary part are received. These 

 pyramids consist of parallel bundles of uriniferous tubules, and are 

 partially separated from one another by offshoots of the cortical part, 

 through which the blood-vessels pass outwards from the hi him. 



Fibrinous mould of tube entang- 

 ling epithelial and blood cells, 

 with, /', three crystals of lithic 

 acid in a case of acute desqua- 

 mative nephritis. (JOHNSON.) 



i, a, br. of renal artery ; c, Mai- 

 pighian capsule ; e, e', efferent 

 vessel ending in plexus, /, on 

 tubule. 



A uriniferous tubule begins in the cortex in a dilatation like a 

 Florence flask (Malpighian capsule), in which a branch of artery and 

 vein form a tuft (glomerulus\ from which the watery- part of the urine 

 transudes, to escape at last by the apex of the pyramid (papilla) into 

 the sinus of the ureter. The tubule has a continuous epithelial lining. 

 Blood in the urine may be due to rupture of the engorged vascular 



