580 BLOOD-VASCULAR SYSTEM OF THE HORSE 



external border of tlio rectus alxlominis and anastomoses in the umbilical region 

 with the anterior abdominal artery (Figs. 272). It sui)plies l)ranches to the rectus 

 and obliquus internus nuiscles. 



(2) The external pudic artery (A. pudenda externa) descends on the inguinal 

 ligament through the inner part of the inguinal canal and emerges at the inner 

 angle of the external ring. In the male it divides into the subcutaneous abdominal 

 artery and the dorsal artery of the penis. The former runs forward a short distance 

 from the linea all)a, and gives branches to the superficial inguinal lymph glands, 

 the sheath, and the scrotum. The latter passes to the dorsum penis and ends at 

 the glans as the arteria glandis. It gives off collateral branches (Rami profundi 

 penis) to the corpus cavernosum, one of which usually passes backward and anasto- 

 moses with a branch of the obturator artery. Branches are also supplied to the 

 superficial inguinal lymph glands, the prepuce, and the scrotum. In the female the 

 mammary artery takes the place of the dorsal artery of the penis; it plunges into 

 the base of th(^ mammary gland. 



2. The deep femoral artery (A. profunda femoris) arises either by a common 

 trunk with the prepubic or a little distal to it (Fig. 451). It passes backward and 

 downward across the inner face of the femoral vein, then below the pubis in the 

 space between the hip joint and the pectineus muscle. On reaching the obtura- 

 tor externus it inclines more ventrally and outward, passes out between the inter- 

 nal border of the femur and the quadratus femoris, and ramifies in the biceps 

 femoris and semitendinosus. It supplies large collateral branches to the adduc- 

 tor muscles and twigs to the deep inguinal lymph glands and the hip joint. 



3. The anterior femoral artery (A. femoralis cranialis) arises a little distal to 

 the preceding vessel from the opposite side of the femoral trunk. It passes forward, 

 outward, and a little downward across the deep face of the sartorius, and dips in 

 between the rectus femoris and vastus internus (Fig. 451). It is related extern- 

 ally to the ilio-psoas and the femoral nerve. 



In some cases this artery is replaced by a large branch of the external circumflex, which 

 passes between the ilio-psoas and rectus femoris and enters the interstice between the latter 

 muscle and the vastus internus. 



4. Innominate muscular branches (Rami musculares) of variable size and 

 arrangement are given off to the muscles of this vicinity. 



5. The saphenous artery (A. saphena) is a small vess(4 which arises from the 

 femoral about its middle or from a muscular branch, and emerges between the 

 sartorius and gracilis or through the latter to the inner surface of the thigh (Fig. 

 457). It is joined by the large saphenous vein and the saphenous nerve and 

 passes down superficially on the fore part of the gracilis, continues on the deep 

 fascia of the leg, and divides above the hock into two branches, which accom- 

 pany the radicles of the vein. It gives off cutaneous twigs and anastomoses with 

 the recurrent tibial artery. 



In some cases this anastomosis docs not occur. The artery may be larger and directly 

 continuous with the internal tarsal artery. 



6. The articular branch (A. gcniu suprema) is a slender artery which arises 

 from the femoral just before it passes through the adductor. It descends along the 

 posterior l)ord('r of the vastus internus to the inner surface of the stifle joint, where 

 it ramifies. 



7. The nutrient artery of the femur (A. nutritia femoris) is given off" at the 

 middle of the femur and enters the nutrient foramen. 



8. The posterior femoral or femoro-popliteal artery (A. femoris caudalis) is a 

 large vessel which arises from the ])osterior face of the femoral just before the trunk 

 passes between the two heads of the gastrocnemius (Fig. 455). It is very short 

 and divides into two branches. The ascending branch passes upward and outward 



