THE INTERNAL ILIAC ARTERY. 



809 



arteries. The portions of the arteries which remain patent form the main stems of the internal 

 ihacs, the hypogastric axes and the superior vesical arteries ; what are spoken of as the main 

 stems of the anterior divisions of the internal iliacs are really the common trunks by which 

 the sciatic and internal pudic arteries arise from the liypogastric. 



In the arrangement of the branches of the foetal hypogastric arteries four types may 

 be recognized, and corresponding to each of these is an arrangement of the adult internal 

 iliac branches. Leaving out of consideration for the present the smaller branches, the first 

 type is that in which two large trunks arise from the hypogastric, the posterior one being 

 the gluteal and the anterior a trunk which divides into the pudic and sciatic. The adult 



Fig. 724. 



Obturator artery. 



Anterior superior 



spine of ilium 



Deep circumflex *^ 



iliac artery 



External iliac arterj 



external iliac vein 

 Obturator vein 



Deep epigastric artery 



Vas deferens 



Artery of vas deferens' 



Middle sacral artery 



Right common iliac artery 



Ilio-lumbar artery 



Internal iliac artery 



Posterior trunk of internal iliac 



Superior gluteal artery 



Single trunk dividing into 

 two lateral sacral arteries 



Pyriformis muscle 



Anterior trunk of 



internal iliac 

 Superior hemorrhoidal 

 from inferiormesenteric 



Rectum 



Superior vesical artery 



Middle vesical artery 

 Inferior vesical artery 

 Sciatic artery 



Internal pudic 

 artery 



Right and left 

 middle hem- 

 orrhoidal arteries 



Spine of ischium 



Seminal vesicles 

 Left ureter 



Anus 

 Prostate 



Internal pudic 

 artery, in ischio- 

 rectal fossa 



Symphysis pubis 



Bladder 

 Right dorsal artery of pt.iis 



Left dorsal artery of penis ^ / / / / Tuber Ischii 



Left corpus cavernosum Corpus Membranous Bulbo-cavemosus muscle 



spongiosum urethra 



Dissection of pelvis of male, showing right internal iliac artery and its branches. 



condition which results from this arrangement is that described above, the main stem of the 

 internal iliac appearing to divide into two divisions, from the anterior of which the hypogastric 

 axis arises. 



The second type is that in which the three large vessels arise independently from the hypO' 

 gastric, the resulting adult condition closely resembling that produced from the first type, except 

 that the hypogastric axis seems to arise from the internal pudic, the separation of the anterior 

 division into its two terminal branches occurring high up. 



The third type is that in which the gluteal and sciatic arteries arise by a common trunk 

 from_ the hypogastric, the pudic remaining distinct. In the adult, in such cases, the anterior 

 division gives rise to the hypogastric axis and the internal pudic, the sciatic arising from the 

 posterior division. 



Finally, in the fourth type, which is of rare occurrence, all three large vessels arise from a 

 common stem, in which case there will be no apparent separation of the adult internal iliac into 

 an anterior and a posterior division. 



