454 ABDOMEN 



front of the roots of the sacral nerves as they issue from the 

 anterior sacral foramina. 



Pelvic Blood- Vessels. The pelvic arteries, in the male, 

 are the following : 



1. The hypogastric and its branches (upon each side). 



2. The middle sacral I (near the median lane) . 



3. The superior hsemorrhoidal J v 



Arteria Hypogastrica (O.T. Internal Iliac Artery). Each 

 hypogastric artery is the medial terminal branch of the corre- 

 sponding common iliac artery ; it is a short, wide vessel, about 

 38 mm. (one and a half inches) long, and it is smaller in the 

 adult than the external iliac artery. It commences opposite 

 the sacro-iliac articulation, at the level of the lumbo-sacral 

 articulation ; it runs downwards and backwards in the pelvis, 

 and ends, near the upper border of the greater sciatic notch, 

 by dividing into an anterior and a posterior division. 



Relations. To its lateral side are the obturator nerve, and, 

 at a higher level, the external iliac vein, which separates it from 

 the medial border of the psoas major (Figs. 216, 224). In 

 front is the ureter, and behind is the hypogastric vein (Fig. 

 216). Medially, it is covered by peritoneum, which separates 

 the right artery from coils of the ileum, and the left from 

 the pelvic colon. In the female the ovary and the ovarian 

 end of the uterine tube are anterior relations of the artery 

 and of the ureter, from both of which they are separated by 

 the parietal peritoneum. 



Condition in the Foetus. The condition of the hypogastric 

 artery in the foetus is very different. It is twice as large as 

 the external iliac artery. Instead of terminating at the sciatic 

 notch it runs forwards, and ascends, on the posterior aspect 

 of the anterior abdominal wall, to the umbilicus, through 

 which it passes, in company with its fellow of the opposite 

 side and the umbilical vein. Outside the abdominal cavity 

 the hypogastric arteries enter the umbilical cord, and, twining 

 spirally round the umbilical vein, they reach the placenta, 

 where the impure blood which they carry is brought into 

 relation with the maternal blood. 



After birth, when the umbilical cord is ligatured and 

 divided, a portion of each hypogastric artery, from the 

 umbilicus to the sciatic notch, undergoes atrophy, and is 

 ultimately converted into a fibrous cord known as the 



