1264 



THE URO-GENITAL SYSTEM. 



/^--^ Cortical substance of kidney 

 L 



Pyramid 



Basal part 

 of pyramid 



The right and left colic arteries, or their branches, as they pass laterally to reach the 

 colon, are often related to the anterior aspects of the corresponding kidneys. The splenic 

 vessels pass laterally in front of the left kidney (Fig. 979). 



The anterior surface of a kidney which has been hardened in situ is, like the 

 posterior surface, not uniformly rounded, but marked by a series of impressions 

 corresponding to the different structures which lie in contact with it. In the case 

 of each kidney, the most prominent region on the anterior surface lies below the 

 level of the middle of the kidney, and corresponds to the thickest part of the organ. 



From this promin- 

 ence on the anterior 

 surface a series of 

 more or less flattened 

 planes slope away to- 

 wards the borders of 

 the kidney. These 

 flattened areas are the 

 impressions formed 

 by the viscera which 

 lie on the anterior 

 surface of the 

 kidney. 



In the case of the 

 right kidney, three 

 impressions can usu- 

 ally be distinguished 

 on the anterior sur- 

 face. One occupies 

 the whole of the 

 upper part of the 

 organ, and is known 

 as the impressio he- 

 patica ; another 

 stretches from the 

 most prominent point 

 to the inferior end of 

 the kidney, and is 

 related to the colon ; 

 while the third ex- 

 tends along the 

 medial margin, below 

 the hilum, and is in 

 contact with the 

 second part of the 



Branch of renal __j 

 artery 



-Pyramid 



Radiate part ["medullary rays "] of cortex 7 "'' 



FIG. 985. LONGITUDINAL SECTION THROUGH THE KIDNEY. 



The vessels and fat have been removed to give a view of the wall of the kidney 

 sinus. The points where the vessels enter the kidney substance are seen as 

 holes in the sinus wall. 



duodenum (Fig. 9 79). 



The relative sizes of these three areas or impressions vary much in different specimens. 

 On the left kidney, also, three more or less defined, flattened impressions slope 

 towards the borders of the organ from the most prominent part of the anterior 

 surface. One of these, on the superior and lateral part of the kidney, is the splenic 

 impression ; another, extending downwards to the lower end of the kidney, is for 

 the jejunum, or for the jejunum and colon ; the third, above and in the region of the 

 hilum, is called the impressio gastrica, and corresponds to the position of the over- 

 lying stomach. Only a small portion of this impression is in direct contact with 

 the stomach, since the pancreas and a part of the suprarenal gland intervene 

 between the stomach and the kidney (Fig. 979). 



It is common to find the left kidney thicker and less flattened antero-posteriorly than 

 the right, the impressions, or "facets," upon its surface being at the same time bett( 

 marked. With this probably is to be associated the fact that floating kidney is mor 

 rarely met with on the left than on the right side of the body. 



