chap. xvi. j THE ABDOMINAL PARIETES. 265 



ligament will correspond to the course of the common 

 and external iliac arteries. The first two inches of 

 this line would cover the common iliac, the remainder 

 the external. 



The coeliac axis comes off opposite the lower part 

 of the twelfth dorsal vertebra, at a spot about four or 

 five inches above the navel, and that corresponds 

 behind to the twelfth dorsal spine. The superior 

 mesenteric and suprarenal arteries are just below the 

 axis. The renal vessels arise about half an inch below 

 the superior mesenteric, opposite a spot some 3|- 

 inches above the umbilicus, and on a level behind 

 with the gap between the last dorsal and first lumbar 

 spines. The inferior mesenteric artery comes off from 

 the aorta about one inch above the umbilicus. The 

 deep epigastric artery follows a line drawn from the 

 middle of Poupart's ligament to the umbilicus. Along 

 the same line may sometimes be seen the superficial 

 epigastric vein. 



The abdominal " rings " will be referred to in the 

 paragraph on hernia. 



Anterior abdominal parietes. The skin 

 over the front of the abdomen is loosely attached in the 

 region of the groin. This condition is taken advantage 

 of in certain operations, e.g.. Wood's procedure for the 

 radical cure of hernia. It also allows of the incision 

 for herniotomy in the inguinal region being made by 

 transfixing a fold of skin that has been pinched up 

 over the external ring. The skin is more adherent to 

 the deeper parts in the middle line than elsewhere, but 

 not so adherent as to hinder the spread of inflammation 

 from one side of the abdomen to the other. In cases 

 of great obesity two transverse creases form across 

 the belly, one crossing the umbilicus and the other 

 passing just above the pubes. In the former of the 

 two creases the navel is usually hidden from sight. 

 In cases of anchylosed hip-joints transverse creases are 



