THE KIDNEYS. 1083 
It is probable that some at least of the depressions on the posterior aspect of the kidney are 
produced after death, and are caused by the weight of the other abdominal organs pressing the 
kidney backwards against the more resisting structures of the abdominal wall, at a time when 
the muscles behind the kidney have become flaccid. 
The outer border in its middle and lower part is rather a surface than a 
border, and looks for the most part directly backwards; resting on the anterior 
surface of the posterior tendon of the transversalis muscle, it lies to the outer side 
Area for 
diaphragm 
<— diaphragm Area for 
= SS : : S diaphragm 
a 
(h- 
Area for 
transversalis 
tendon 
Area for Area for psoas 2 
quadratus Z 
Inmborum b ZB. 6 Area for 
Za transversalis 
g tendon 
Area for psoas Area for 
quadratus 
lum borum 
Fic. 729.—TuHE KIDNEYS VIEWED FROM BEHIND. Same specimen as Fig. 730. The dotted lines mark out 
the areas in contact with the various muscles forming the posterior abdominal wall. 
a. Depression corresponding to the transverse process of the first lumbar vertebra. 
6, Depression corresponding to the transverse process of the second lumbar vertebra. 
c. Depression corresponding to the twelfth rib. 
of the quadratus hunborum. The outer border is narrowest above, and widest just 
below its middle point, corresponding to the greater thickness of this part of the 
kidney. 
In many ways it would be more satisfactory to apply the term muscular surface (facies 
muscularis) collectively to the areas described here as posterior surface and outer border ; in like 
manner the term visceral surface (facies visceralis) might be suitably applied to the so-called 
anterior surface of the organ. The edge separating the visceral from the muscular surface is the 
actual outer border of the kidney. 
Anterior Relations and the Anterior Surface of the Kidney.—The anterior 
relations of the kidneys not only differ on the two sides of the body, but also many 
of the structures related to the anterior surface of each kidney undergo frequent 
changes in position during life. 
A small area on the upper part of the anterior surface of the right kidney is in 
relation to the corresponding suprarenal capsule (Fig. 750). The rest of the upper 
part of the anterior surface is in contact with the under surface of the liver. The 
suprarenal capsule is bound to the kidney by connective tissue, while the part of 
the kidney in relation to the liver is, like the liver itself, covered by peritoneum, 
and so the two organs, although closely applied, are really separated by a part of 
the general peritoneal cavity. In front of the lower end of the right kidney are 
usually found two parts of the alimentary canal—namely, the descending part of 
the duodenum and the hepatic flexure, or the commencement of the transverse 
colon. The part of the kidney related to the duodenum lies to the inner side of 
the area which touches the colon, but the exact amount of the kidney in contact 
with each of these two parts of intestine varies much in different subjects. Both 
