THE INFERIOR VESICAL ARTERY 609 



maximus and beneath the superior gluteal vein, and in front of the superior 

 gluteal nerve. It here breaks up into two chief branches, a superficial and a 

 deep. Its emergence from the pelvis is indicated on the surface by a point 

 situated at the junction of the posterior with the middle third of a line drawn 

 from the anterior superior to the posterior superior spine of the ilium. 



The branches of the superior gluteal artery are : — 



(a) Within the pelvis, branches are distributed to the obturator internus, the 

 piriformis, the levator ani, the coccygeus, and the pelvic bones. 



ih) External to the pelvis, the artery divides into a superior and an inferior 

 branch. 



(i) The superior branch [ramus superior] breaks up into a number of large vessels for the 

 supply of the upper portion of the gluteus maximus, some of them piercing the muscle and supply- 

 ing the skin over it, and anastomosing with the posterior branches of the lateral sacral arteries; 

 whilst one of larger size, emerging from the muscle near the iliac crest, anastomoses with the 

 deep circumflex iliac artery. The lower branches to the muscle anastomose with branches of 

 the inferior gluteal (sciatic). 



(ii) The inferior branch [ramus inferior] subdivides into two branches — One skirts along 

 the line of origin of the gluteus minimus (fig. 490), between the gluteus medius and the bone, 

 and, emerging in front from beneath these muscles under cover of the tensor fascise lata;, anas- 

 tomoses with the ascending branch of the lateral circumflex and the deep circumflex iliac arter- 

 ies. The other passes forward between the gluteus medius and minimus, accompanied by the 

 branch to the tensor fasciae latse of the inferior division of the superior gluteal nerve, toward the 

 greater trochanter, where it anastomoses with the ascending branch of the lateral circumflex. 

 It supplies branches to the contiguous muscles and to the hip-joint. The inferior branch before 

 its division gives off the external nutrient artery of the ihum. 



The inferior gluteal [a. glutea inferior], is one of the terminal branches 

 of the anterior division of the hypogastric artery. It leaves the pelvis below the 

 piriformis muscle, and immediately breaks up into a number of diverging branches. 

 The largest enter the gluteus maximus muscle, where they anastomose with the 

 superior gluteal branches. Others pass to the hip-joint and the deep muscles 

 around it; a third group passes downward to the hamstring muscles and anas- 

 tomoses with the medial and lateral circumflex and first perforating; a fourth 

 slender branch, the sciatic artery [a. comitans n. ischiadici], accompanies the 

 sciatic nerve (fig. 490). 



Visceral Branches of the Hypogastric Artery 



1. THE UMBILICAL ARTERY 



The umbilical artery in the foetus is the continuation of the hypogastric. 

 Passing forward along the side of the pelvis, it runs beneath the lateral reflexion of 

 peritoneum from the bladder, where, after giving off one or more vesical branches, 

 it ceases to be pervious and passes on to the side and upper part of the bladder. 

 Thence it ascends in the lateral umbilical fold, as a fibrous cord [ligamentum 

 umbilicale laterale], to the umbilicus, where it is joined by its fellow of the 

 opposite side. As it lies lateral to the bladder it is crossed by the ductus deferens. 



The branches of the umbilical artery are: — (1) Superior vesical arteries, the 

 lowest of which is sometimes called (2) the middle vesical artery (fig. 489). 



The superior vesical arteries [aa. vesicales superiores] ramify over the upper surface of the 

 bladder, anastomosing with the artery of the opposite side and with tlie middle and inferior 

 vesical below. They give off the following branches: — (a) The urachal branches which pass 

 upward along the urachus. (6) The ureteric branches pass to the lower end of the ureter, 

 and anastomose with the other ureteric arteries, (c) The middle vesical may come off from 

 one of the superior vesicals or from the umbilical. It is distributed to the sides and base of the 

 bladder, and anastomoses with the other vesical arteries. 



2. THE INFERIOR VESICAL ARTERY 



The inferior vesical artery [a. vesicalis inferior] arises from the anterior 

 division of the hj^pogastric, frequently in common with the middle hsemorrhoidal, 

 and passes downward and medially to the fundus of the bladder, where it breaks 

 up into branches which ramify over the lower part of the viscus. It gives off 

 branches to the prostate, which supply that organ and anastomose with the 

 arteries of the opposite side by means of descending arteries which pass through 



39 



