190 THE SURGICAL ANATOMY OF THE HORSE 



the adult animal, however, the vessel is almost entirely obliterated, and is 

 represented by a fibrous cord, which is pervious only for a short distance. 

 It gives off one or two small branches to the fundus of the bladder, and 

 after the detachment of these its lumen disappears. 



II. The Internal Pudic Artery. — This is sometimes referred to as the 

 artery of the bulb. In the male subject its description is as follows : 

 Leaving the internal iliac artery near its origin by a trunk which is 

 common to this and the umbilical artery, it runs obliquely downwards 

 and backwards along the deep face of the great sacro-sciatic ligament, 

 though it may be found in the texture of the ligament itself. Though 

 very slender, it is a vessel of considerable length. It enters the pelvic 

 cavity and runs alongside the prostate gland and the gland of Cowper, 

 and then curves round the ischial arch to enter the bulb of the urethra. 



During its course the internal pudic artery gives off a number of 

 small branches to the muscles in relation to the great sacro-sciatic liga- 

 ment. The vesico-prostatic artery is also a branch of this vessel. This 

 branch takes a sinuous course backwards, and distributes branches to the 

 posterior portion of the bladder, to the vesiculs seminales, the prostate 

 gland, and also to the urethra. The internal pudic artery also detaches 

 hsemorrhoidal and perineal branches. 



In the female the internal pudic artery ends near the vagina by 

 splitting into a number of branches which are distributed to the 

 vagina, vulva, and rectum. It gives off a branch which is analogous to 

 the vesico-prostatic artery of the male and which is called the vaginal 

 artery. 



Probably the simplest method of dealing with the terminal divisions 

 of the internal iliac artery is that recommended by Shave, who refers to 

 them as three main trunks termed respectively internal, middle, and 

 external. 



I. The internal trunk is the lateral sacral artery, which commences 

 near the lumbo-sacral joint and takes a course backwards along the 

 inferior aspect of the sacrum near the inferior sacral foramina, crossing 



