1 894 HUMAN ANATOMY. 



dissection with the finger, and either stitched in place, decapsulated, or opened, in 

 accordance with the indications. 



It may be noted that bleeding from the separation of the capsule is comparatively 

 trifling; and that if the kidney itself is to be incised, the fact that its blood-supply is 

 naturally divisible into two independent segments anterior and posterior which 

 are completely separated by the renal pelvis, and the vessels of which are given off 

 from the main trunk of the renal artery (Hyrtl), indicates, as the line of safety, the 

 convex posterior or outer border. When the pelvis of the kidney is distended with 

 fluid, a white line on that border (Brodel's line), is said to indicate the relatively avas- 

 cular area. The anterior vascular division is said to carry three-fourths of the arterial 

 blood-supply and the posterior division the remaining fourth (Brodel), so that in the 

 majority of cases the posterior surface of the kidney would furnish the lesser quantity 

 of blood. 



For removal of the kidney (nephrectomy) the oblique incision may be prolonged 

 forward, the peritoneum being detached and pushed in that direction ; or a vertical 

 incision running downward from it may be added ; or, if the nephrectomy is to be 

 done for the removal of an exceptionally large tumor, the anterior or transperitoneal 

 route may be adopted and the incision made in either the linea semilunaris or the 

 linea alba, the outer layer of the mesocolon being opened to gain access to the retro- 

 peritoneal space. The nerves and vessels, as they enter the hilum of the kidney, the 

 M in lying in front, constitute the " pedicle." The ureter lies more posteriorly and 

 on a slightly lower plane. The irregularities in the division, distribution, and points 

 of entrance of the renal artery should be remembered, as should also on the right 

 side the proximity of the vena cava during the separation of close adhesions. 



In all the lumbar operations upon the kidney the colon may present in the 

 wound after the transversalis fascia has been opened, and should be looked for and 

 displaced antero-externally to avoid danger of wounding it. 



THE RENAL DUCTS. 



The duct of the kidney the canal which receives the urine as it escapes from 

 the kidney and conveys it to the bladder consists of a short dilated and sub- 

 divided upper segment, the renal pelvis, and a long, narrow, tubular lower segment, 



the ureter. Since not only 



FlG - I(5l 4- these but also the papillary 



ducts of the kidney are de- 

 veloped from a common out- 

 growth from the Wolffian 

 duct, the renal duct stands 

 in most intimate relations 

 with the renal substance. 



The pelvis of the 

 kidney (pelvis renalis), al- 

 though beginning and lying 

 chiefly within the sinus, ex- 

 tends beyond the latter, 

 passing downward to be- 

 come continuous with the 

 ureter. Its widest part, just 

 within the hilum, presents an 

 u n broken convex postero- 

 mesial surface, its opposite 

 side, directed towards the 

 renal substance, being inter- 

 rupted by the subdivisions 

 of the pelvis. These include 

 the pdvfa into an n^cr and a lower segment (calvccs majores) 

 extending towmrda th,- respective poles of the kidney. 'Each of these segments 

 esa gnttp oi from four to six smaller conical passages, the cafyces or in/un- 



Cftl 



Cat obtained by corrosion, showing two forms of renal pelvis- 



.I. iiMial l\|.r , /,', \:n j:tti<m. 



