816 THE VASCULAR SYSTEM. 
pierces the deep fascia, and terminates in the scrotum, where it anastomoses with 
the superficial perineal and superficial external pudic arteries, and with the 
cremasteric branch of the deep epigastric artery. 
(4) The profunda artery (a. profunda femoris, Fig. 573) is a large branch only 
slightly smaller than the continuation of the femoral artery. It arises about an 
inch and a half below Poupart’s ligament, from the outer side of the femoral artery. 
Curving backwards and inwards, it passes behind the latter vessel, and runs down- 
wards, close to the inner aspect of the femur, to the lower third of the thigh, where 
it perforates the adductor magnus and passes to the back of the thigh. Its termina- 
tion is known as the fourth perforating artery. As the profunda descends it les 
upon the ilacus, the pectineus, the adductor brevis, and the adductor magnus. — It 
is separated from the femoral artery by its own vein, by the femoral vein, and by 
the adduetor longus muscle behind which it passes. 
Branches. —(«) Muscular branches are given off from the profunda both in Searpa’s 
triangle, and whilst it lies between the adductor muscles ; many of them terminate in the 
adductors, others pass through the adductor magnus, and terminate in the hamstrings, 
where they anastomose with the transverse branch of the internal circumflex and with 
the upper muscular branches of the popliteal artery. 
(L) The external circumflex artery (a. circumflexa femoris lateralis, Figs. 573 and 574) 
springs from the outer side of the profunda, or occasionally from the femoral artery 
above the origin of the profunda. It runs outwards across the front of the iliacus, and 
between the superficial and deep branches of the anterior crural nerve, to the outer border 
of Searpa’s triangle; then, passing beneath the sartorius and the rectus femoris, it terminates 
by dividing into three terminal branches—the ascending, the transverse, and the descend- 
ing. Before its termination it supplies branches to the muscles mentioned and to the 
upper part of the crureus. 
G.) The ascending terminal branch (raimus ascendens) runs upwards and outwards, beneath the 
rectus femoris and the tensor faseiz femoris, along the anterior intertrochanteric line, to the 
anterior borders of the gluteus medius and minimus, between which it passes to anastomose with 
the deep branches of the gluteal artery. It supplies twigs to the neighbouring muscles, anasto- 
moses with the gluteal, the deep circumflex iliac, and the transverse branch of the external 
circunflex arteries, and, as it ascends along the anterior intertrochanteric line, gives off a branch 
which passes between the two limbs of the Y-shaped ligament into the hip-joint. (u.) The 
transverse terminal branch is small ; it runs outwards between the crureus and the rectus femoris, 
passes into the substance of the vastus externus, winds round the femur, and anastomoses with 
the ascending and descending branches, with the perforating branches of the profunda, and with 
the sciatic and internal circumflex arteries. (i1i.) The descending terminal branch (ramus 
descendens) runs downwards beneath the rectus and along the anterior border of the vastus 
externus accompanied by the nerve to the latter muscle. It anastomoses with the transverse 
branch, with twigs of the inferior perforating arteries, with the anastomotic branch of the femoral, 
and with the superior external articular branch of the popliteal artery. 
(c) The internal circumflex artery (a. circumflexa femoris medialis, Fig. 573) springs 
from the inner and back part of the profunda, at the same level as the external circumflex, 
and runs backwards, through the floor of Scarpa’s triangle, passing between the psoas and 
the pectineus ; crossing the upper border of the adductor brevis it is continued backwards 
beneath the neck of the femur, and passes between the adjacent borders of the obturator 
externus and the adductor brevis to the upper border of the adductor magnus, where it 
divides into two terminal branches, a transverse and an ascending. 
Branches.—(i.) An articular branch (ramus acetabuli) is given off as the artery passes 
beneath the neck of the femur. It ascends to the cotyloid notch where it anastomoses with 
twigs from the posterior branch of the obturator artery, and it sends branches into the cotyloid 
eavity and along the ligamentum teres to the head of the femur. (ii.) Muscular branches are 
given off to the neighbouring muscles. The largest of these branches usually rises immediately 
before the termination of the artery, it descends on the anterior aspect of the adductor magnus 
and anastomoses with the muscular branches of the profunda artery. (1ii.) The ascending terminal 
branch (ramus profundus) passes upwards and outwards, between the obturator externus and the 
quadratus femoris to the digital fossa of the femur, where it anastomoses with branches of the 
gluteal and the sciatic arteries. (iv.) The transverse terminal branch (ramus superficialis) runs 
backwards between the lower border of the quadratus femoris and the upper border of the 
adductor magnus to the hamstring muscles. It anastomoses under the lower part of the gluteus 
maximus with the sciatic and first perforating arteries and with the transverse branch of the 
external circumflex, and in the substance of the hamstrings with the muscular branches of the 
protunda. 
