THORAX AND ABDOMEN OF THE HORSE 



141 



typical shape of the kidneys, there are often deviations from the type. 

 With no great infrequency the right gland niay be nearly or quite as 

 elongated as the left, and the left may sometimes have a form 

 simulating that of the right. 



The dorsal surface (facies dorsalis) of the right kidney is convex and 

 in contact with the diaphragm and the psoas muscles in about equal 

 proportion. The corresponding surface of the left kidney has only a 

 small area of contact with the diaphragm, most of it being related to 

 the psoas muscles. Consequently, the surface is crossed longitudinally 

 by a low ridge, produced by the shallow groove between the major and 

 minor psoas muscles, separating two gentle slopes caused by contact 

 with these muscles. 



Right adrenal. 

 Pancreas. I y^„^ ^^^^ caudalis. 



I Aorta. 

 ' I Left adrenal. 



Pancreas. 



Liver. 



Duodenum. 



Caecum. 



Duodenum. 



Small colon. 



Fig. 65. — Outline of the ventral surface of the kidneys, to show the relative 

 position, shape and relations of the two organs. 



The ventral surface (facies ventralis) may be convex in both organs, 

 but most frequently that of the right kidney is flattened or even slightly 

 hollowed. The relations of the surface are naturally different in the two 

 organs. The right kidney is in contact with the liver, pancreas, dorsal 

 sac of the caecum, and possibly also the duodenum ; and is covered by 

 peritoneum along a narrow lateral area only. Nearly the whole of the 

 ventral surface of the left kidney has a peritoneal covering, and it is 

 related to some of the coils of the small intestine and small colon, and 

 (possibly) the left end of the pancreas. 



The rounded cranial end (extremitas cranialis) of the right kidney 

 is received into the impressio renalis of the liver ; while the correspond- 

 ing end of the left gland is generally in contact with the tail of the 

 pancreas, but may touch the stomach if this organ is distended. 



The flattened caudal end (extremitas caudalis) of the right kidney 



