THE ABDOMEN 841 



from the foetus to the placenta of the mother. The hypogastric artery- 

 passes forwards to the posterior surface of the anterior wall of the abdomen, 

 being crossed by the vas deferens. It then ascends to the lower part of the um- 

 bilicus, where it leaves the abdomen with its fellow. Beyond the umbihcus the 

 hypogastric is known as the umbilical arter>', and the two umbilical arteries, 

 together with the umbilical vein, form the umbilical cord, in which the arteries 

 describe spiral coils around the vein. The arteries convey the impure blood to 

 the placenta, where it is purified, after which it is returned to the abdomen of 

 the foetus by the umbilical vein. After birth, there being no further use for 

 the placental circulation, the umbilical cord is tied, and the child separated from 

 the mother. Thereafter the hypogastric arteries become impervious, and each 

 is converted into a fibrous cord. The obliteration, however, does not involve the 

 first I ^ inches of the vessel, which persist as the internal iUac artery of the adult. 

 Moreover, the proximal end of the fibrous cord representing the obliterated 

 hypogastric remains pervious also, and, being connected with the anterior 

 division of the internal iliac, it furnishes the superior vesical artery or arteries. 

 This pervious portion lies along the side of the pelvis beneath the peritoneum, 

 where it is crossed by the vas deferens in the male, and the round Ugament of 

 the uterus in the female. The foetal hypogastric artery gives off the sciatic, 

 which is the primitive main artery of the lower Umb, until the external iliac, 

 which becomes the femoral, is developed. 



Branches. — ^These are subject to much variation. In normal 

 cases they arise from the two terminal divisions, anterior and 

 posterior, some of them being parietal in their distribution, which 

 will be indicated by the letter P, whilst others are visceral, which 

 wiU be indicated by the letter V. The branches are las follows : 



Anterior Division. Posterior Division. 



Visceral. Parietal. Parietal. 



Superior vesical. Obturator. Ilio-lumbar. 



Inferior vesical. Internal pudic. Lateral sacral. 



Middle hemorrhoidal. Sciatic. Gluteal. 



In the female the inferior vesical artery may be replaced by the 

 vaginal, or the vaginal may be an independent branch, and the 

 uterine artery is always a special branch. 



Anterior Division. — ^The superior vesical artery (V) arises from the 

 pervious portion of the fibrous cord which represents the foetal 

 hypogastric artery, and at once breaks up into several twigs which 

 frequently have independent origins. They are distributed to the 

 upper portion of the bladder, and anastomose with the vesical of 

 the obturator, and the inferior vesical of the same side, and with the 

 superior vesical of the opposite side. The superior vesical furnishes 

 the following branches : urachal to the urachus ; ureteric to the 

 lower end of the ureter ; and deferential (as a rule) to the vas 

 deferens, though this branch may arise from the inferior vesical. 

 The deferential artery, which is usually of small size, divides into a 

 descending and an ascending branch. The descending branch passes 

 downwards to supply the ampulla of the vas deferens, and the 

 vesicula seminalis. The ascending branch accompanies the vas 

 deferens through the internal abdominal ring and inguinal canal 

 into the scrotum, supplying the vas deferens, and giving a few twigs 



