UTERINE— VA GINAL—OBTURA TOR 



571 



both in front and behind in the middle Hne of tlie cervix on to tlie vagina, and 

 forms, with liranehes of the vaginal arteries, the so-called azygos artery of the 

 vagina. 



5. THE VAGINAL ARTERIES 



The vaginal arteries come ofif separately from the anterior division of the 

 internal iliac, or one or more of them may arise in common with the inferior 

 vesical, uterine, or middle hsemorrhoidal arteries. They are usually two or three in 

 number. They pass through the pelvic connective tissue to the side of the vagina, 

 supplying its Avails, and anastomosing with the corresponding arteries of the oppo- 

 site side, with each other, and witli tortuous branches from the artery of the cervix, 

 a branch of the uterine. "With this vessel they form a more or less vertical trunk 

 in the median line of the vagina, both back and front. This vessel is known as the 



Fig. 370.— Scheme of the Ovaeiax axd Uteeixe and Vagixal Arteries. 



Branch 



Cervical branch 



Coronal artery 



FIMBRIATED 



Branch Branches 

 Uterine to round to to EXTREMITY OF 



branch ligament isthmus ampulla FALLOPIAN TUBE 



Ovarian branches 



Uterine artery 

 Internal iliac artery 



Vaginal arteries 



azygos artery of the vagina. The lower vaginal arteries extend to the bulb of 

 the vestibule, where they conununicate with the bulbar branch of the internal 

 pudic. Small branches extend also on to the rectum. 



6. THE OBTURATOR ARTERY 



The obturator artery comes off from the anterior division of the internal iliac 

 at about the same sjiot as the hypogastric. Occasionally it arises from the posterior 

 division. It runs forward and downwards a little below the brim of the pelvis, 

 having the obturator nerve al)Ove, and the obturator vein below. It here lies 

 between the peritoneum and the pelvic fascia, but pierces the fascia to gain the 

 obturator canal, the aperture in the upper and outer part of the ol>turator mem- 

 brane. In this course it is crossed by the vas deferens. On emerging from the 

 obturator canal, the artery divides into two branches, an external and an internal, 

 which wind round the margin of the thyroid foramen beneath the obturator 

 externus muscle. 



