828 HUMAN ANATOMY. 



4. The Deep External Pudic Artery. — The deep external pudic artery (a. 

 pudenda externa profunda) (Fig. 732 j arises from the inner surface of the femoral, 

 either a little below the superficial external pudic or in common with that vessel. It 

 passes medially beneath the fascia lata across the femoral vein and the pectineus and 

 adductor longus muscles. It then pierces the fascia lata close to the ramus of the 

 pubis and is distributed to the sides of the scrotum or labium majus, anastomosing 

 with branches of the superficial external pudic and of the superficial perineal branch 

 of the internal pudic. 



5. The Deep Femoral Artery. — The deep femoral artery (a. profunda 

 femoris) (Fig. 733) arises from the outer surface of the femoral, usually about 

 4 cm. below Poupart's ligament, and at first is directed downward parallel to the 

 femoral and to the outer side of that vessel. It then bends medially and passes 

 obliquely behind the femoral artery and vein, and on arriving at the upper border of the 

 adductor longus, passes behind that vessel and is continued downward between it 

 and the adductor magnus, rapidly diminishing in size. Finally it perforates the 

 adductor magnus and terminates in branches to the lower portions of the hamstring 

 muscles. 



Relations. — At first the profunda lies alongside the femoral and is, like it, su- 

 perficial, having in front of it only the fasciae and integument, together with some 

 branches of the anterior crural nerve. Later it lies behind the femoral artery and 

 the femoral and profunda veins, and still later the adductor longus and the adductor 

 magnus. Posteriorly it rests at first upon the ilio-psoas and then successively upon 

 the pectineus, the adductor brevis, and the adductor magnus. 



Branches. — The profunda femoris gives origin to the following branches : ( i ) the external 

 circiunflcx, (2) xh^ infernal circiiiiiflex, (3) the ihreo. perforating arXeuaf.. The terminal por- 

 tion of the profunda, after it has pierced the adductor magnus, is sometimes spoken of as the 

 fourth perforating artery. 



(«) The external circumflex artery (a. circumflexa femoris lateralis) is the largest of the 

 branches of the profunda and arises from it a short distance beyond its origin. It is directed 

 horizontally outward across Scarpa's triangle, resting upon the ilio-psoas muscle and passing 

 between the superficial and deep branches of the anterior crural nerve. It then passes beneath 

 the sartorius and rectus muscles and terminates by dividing into an ascending, a transverse, and 

 a descending branch. The ascending branch passes upward and outward to beneath the tensor 

 vaginae femoris, running along the anterior trochanteric line of the femur, and terminates by anas- 

 tomosing with the gluteal and the deep circurnflex iliac arteries. It sends twigs to the neigh- 

 boring muscles and to the hip-joint. The transverse branch is small and runs directly outward 

 to below the greater trochanter, passing between the rectus and the crureus muscles and through 

 the substance of the vastus lateralis. It unites with branches of the sciatic, internal circumflex, 

 and first perforating arteries to form the crucial anastomosis. The descenditig branch runs 

 downward beneath the rectus muscle, along with the nerve, to the vastus lateralis, and usually 

 extends to the neighborhood of the knee-joint, where it anastomoses with the superior external 

 branch of the popliteus and assists in the formation of the circumpatellar anastomosis. It gives 

 branches to the rectus, crureus, and vastus lateralis. 



{b) The internal circumflex artery (a. circumflexa femoris medialis) arises from the inner 

 surface of the profunda, very nearly opposite the external circumflex. It passes over the surface 

 of the ilio-psoas and beneath the pectineus to reach the anterior surface of the neck of the 

 femur. It then crosses the upper portion of the adductor brevis and adductor magnus and 

 passes along the lower border of the obturator externus and, finallj-, upon the anterior surface 

 of the quadratus femoris, where it divides into its terminal branches. 



(art) The ascending branch (ramus ascendens) passes upward towards the digital fossa of 

 the femur, sending branches to the capsule of the hip-joint and anastomosing with the sciatic 

 and external circumflex arteries. 



{bb) The descending branch (ramus descendens) passes downward and curv^ around the 

 lower border of the quadratus femoris to terminate in the upper portion of the hamstring mus- 

 cles. This branch anastomoses with the sciatic, external circumflex, and first perforating ves- 

 sels to form the crucial anastomosis. In addition, the internal circumflex in its course sends 

 muscular branches to the adjacent muscles and also an articular branch (ramus acetabuli) to the 

 hip-joint. 



(r) The three perforating branches arise in succession from the profunda and pass back- 

 ward, curving around the inner surface of the femur. They perforate the adductor muscles 

 close to the bone, and supply the hamstring muscles and the vastus externus, anastomosing with 

 one another and with neighboring vessels. 



