518 ARTERIES. 



Union icith 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 others from the internal iliac. 



The circumflex iliac artery arises from tbe o'uter 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 that muscle and the Internal Oblique, to anastomose with the ilio- 

 lumbar and gluteal arteries. Opposite the anterior superior spine of the ilium, 

 it gives off 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. 

 These unite into a single trunk which crosses the external iliac artery just above 

 Poupart's ligament, and enters the external iliac vein. 



FEMORAL ARTERY. (Fig. 298.) 



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 forepart 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 

 superior 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 the 

 bone, and between these two parts, the vessel is separated from the bone by a 

 considerable interval. 



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

 covered by the integument, inguinal glands, and the superficial and deep fascia3, 

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



Scarpa's Triangle. Scarpa's triangle corresponds to the depression seen imme- 

 diately 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 Adductor Longus, and above by Poupart's ligament. 

 The floor of this space is formed from without inwards by the Iliacus, Psoas, 

 Pectineus, Adductor Longus, and a small part of the Adductor Brevis muscles; 

 and it is divided into two nearly equal parts by the femoral vessels, which 

 extend from the middle of its base to its apex; the artery giving off in this 

 situation its cutaneous and profunda branches, the vein receiving the deep 

 femoral and internal saphenous veins. In this space the femoral artery rests on 

 the inner margin of the Psoas muscle, which separates it from the capsular 

 ligament of the hip-joint. The artery in this situation has in front of it fila- 

 ments from the crural branch of the genito-crural nerve, and branches from the 

 {interior crural, one of which is usually of considerable size; behind the artery 

 is the branch to the Pectineus from the anterior crural. The femoral vein lies 

 at its inner side, between the margins of the Pectineus and Psoas muscles. The 

 anterior crural nerve lies about half an inch to the outer side of the femoral 

 artery, deeply imbedded between the Iliacus and Psoas muscles. The femoral 

 artery and vein are inclosed in a strong fibrous sheath, formed by fibrpus and 

 cellular tissue, ;nnl by a process of fascia sent inwards, from the fascia lata; the 

 vessels are separated, however, from one another by thin fibrous partitions. 



In lli>' middle third of the thigh, the femoral artery is more deeply seated, being 

 ciive red by the integument, the superficial and deep fascia, and the Sartorius, 

 and is contained in an aponeurotic canal, formed by a dense fibrous band, which 



