ARTERIES OF THE PELVIC LIMB 717 



The renal arteries arise from the aorta close together. The right one passes 

 outward and forward across the dorsal face of the posterior vena cava to the hilus 

 of the kidney. The left one runs backward, but necessarily varies in direction in 

 conformity with the position of the kidney (g. v.). 



The spermatic arteries resemble those of the horse. 



The utero-ovarian arteries are small. 



The five pairs of lumbar arteries derived from the aorta are distributed much 

 as in the horse. The sixth usually comes from the internal iliac artery. 



The middle sacral artery is a vessel about 5 mm. in diameter which continues 

 the aorta. It arises from the dorsal face of the aorta at the angle of divergence of 

 the internal iliacs, runs backward on the pelvic surface of the sacrum a little to the 

 left of the median line, and is continued as the middle coccygeal artery. It gives 

 off small collateral branches to the spinal cord and the muscles of the tail and the 

 lateral coccygeal arteries. The latter may have a common trunk of origin, and 

 each divides into dorsal and ventral branches. The middle coccygeal artery runs 

 through the ventral (hsemal) arches of the coccygeal vertebrae. The coccygeal 

 arteries are connected at pretty regular intervals by segmental anastomoses. 



The internal iliac arteries are much longer than in the horse. Each passes 

 backward on the sacro-sciatic ligament and divides about the middle of the pelvic 

 wall into posterior gluteal and internal pudic branches. The chief differences in 

 its distribution are: (1) A large trunk gives origin to the umbilical and middle 

 uterine arteries. The umbilical artery is usually largely obliterated, and its terminal 

 branches receive their blood through anastomoses with the internal pudic. It 

 gives off near its origin two small vessels, the ureteral artery (A. ureterica) and the 

 deferential artery (A. deferentialis), which accompany the ureter and the ductus 

 deferens respectively. The middle uterine artery (A. uterina media) is very large. 

 It is distributed chiefly to the cornu of the uterus, and compensates for the small 

 size of the utero-ovarian artery. (2) The ilio-lumbar artery is relatively small 

 and is distributed chiefly to the sublumbar muscles. It is sometimes replaced by 

 branches of the circumflex iliac and gluteal arteries. (3) The anterior gluteal 

 artery is commonly represented by several vessels. (4) The obturator artery is 

 represented by several small branches which supply the obturator and adductor 

 muscles. (5) The iliaco-femoral and lateral sacral arteries are absent. The 

 absence of the latter is compensated by the middle sacral and gluteal arteries. (6) 

 The posterior gluteal artery is large. It emerges through the lesser sciatic notch 

 and ramifies in the biceps femoris and adjacent muscles. (7) The internal pudic 

 artery (A. urethro-genitalis) is the direct continuation of the internal iliac. It 

 gives off branches to the rectum, bladder, urethra, and genital organs. In the 

 male it supplies the accessory genital glands and divides into dorsal and deep arteries 

 of the penis; the a. dorsalis penis runs along the dorsum penis to the glans and gives 

 twigs to the prepuce; the a. profimda penis gives off a perineal branch and enters 

 the corpus cavernosum penis. In the female it gives off the large posterior uterine 

 artery, which supplies the posterior part of the uterus and gives branches to the 

 vagina and bladder. It ends as the a. clitoridis, which supplies the clitoris and 

 adjacent parts. 



ARTERIES OF THE PELVIC LIMB 



The external iliac artery has the same course as in the horse. The circumflex 

 iliac artery is large. A branch from it emerges between the abdominal and lumbar 

 muscles near the tuber coxa and ramifies like the terminals of the ilio-lumbar 

 artery of the horse. 



The femoral and popliteal arteries pursue a similar course to those of the horse. 

 The chief differences in their branches are as follows: 



1. The external pudic artery is distributed chiefly to the scrotum in the male. 



