438 ARTERIES. 



margin of the sheath of the Eectus muscle. Having perforated the sheath near 

 its lower third, it ascends vertically upwards behind the Rectus, to which it is 

 distributed, dividing into numerous branches, which anastomose above the umbi- 

 licus with the terminal branches of the internal mammary and inferior intercostal 

 arteries. It is accompanied by two veins, which usually unite into a single trunk 

 before their termination in the external iliac vein. As this artery ascends from 

 Poupart's ligament to the Rectus, it lies behind the inguinal canal, to the inner 

 side of the internal abdominal ring, and immediately above the femoral ring, the 

 vas deferens in the male and the round ligament in the female crossing behind 

 the artery in descending into the pelvis. 



Branches. The branches of this vessel are the cremasteric, which accompanies 

 the spermatic cord, and supplies the Cremaster muscle, anastomosing with the 

 spermatic artery ; a pubic branch, which runs across Poupart's ligament, and then 

 descends behind the pubes to the inner side of the femoral ring, and anastomoses 

 -with offsets from the obturator artery; muscular branches, some of which are 

 distributed to the abdominal muscles and peritoneum, anastomosing with the 

 lumbar and circumflex iliac arteries ; others perforate the tendon of the External 

 oblique and supply the integument, anastomosing with branches of the external 

 epigastric. 



Peculiarities. The origin of the epigastric may take place from any part of the external 

 iliac between Poupart's ligament and two inches and a half above it ; or it may arise below this 

 ligament, from the femoral, or from the deep femoral. 



Union ivith Branches. It frequently arises from the external iliac by a common trunk with 

 the obturator. Sometimes the epigastric arises from the obturator, the latter vessel being fur- 

 nished by the internal iliac, or the epigastric may be formed of two branches, one derived from 

 the external iliac, the other from the internal iliac. 



The circumflex iliac artery arises from the outer side of the external iliac, nearly 

 opposite the epigastric artery. It ascends obliquely outwards behind Poupart's 

 ligament, and runs along the inner surface of the crest of the ilium to about its 

 middle, where it pierces the Transversalis and runs backwards between this 

 muscle and the Internal oblique, to anastomose with the ilio-lumbar and gluteal 

 arteries. Opposite the anterior superior spine of the ilium, it gives oft' a large 

 branch, which ascends between the Internal oblique and Transversalis muscles, 

 supplying them and anastomosing with the lumbar and epigastric arteries. The 

 circumflex iliac artery is accompanied by two veins, which, uniting into a single 

 trunk, cross the external iliac artery just above Poupart's ligament, and enter 

 the external iliac vein. 



FEMOEAL AETEEY. 



The Femoral Artery is the continuation of the external iliac. It commences 

 immediately beneath Poupart's ligament, midway between the anterior superior 

 spine of the ilium and the symphysis pubis, and, passing down the fore part and 

 inner side of the thigh, terminates at the opening in the Adductor magnus, at the 

 junction of the middle with the lower third of the thigh, where it becomes the 

 popliteal artery. A line drawn from a point midway between the anterior supe- 

 rior spine of the ilium and the symphysis pubis to the inner side of the inner 

 condyle of the femur, will be nearly parallel with the course of the artery. This 

 vessel, at the upper part of the thigh, lies a little internal to the head of the 

 femur ; in the lower part of its course, on the inner side of the shaft of this bone ; 

 and between these two points, the vessel is separated from the bone by a consi- 

 derable interval. 



In the upper third of the thigh the femoral artery is very superficial, being covered 

 by the integument, inguinal glands, and by the superficial and deep fascia?, and 

 is contained in a triangular space, called " Scarpa's triangle." 



Scarpds triangle corresponds to the depression seen immediately below the fold 

 of the groin. It is a triangular space, the apex of which is directed downwards, 

 and the sides of which are formed externally by the Sartorius, internally by the 



