THE LOWER LIMB 485 



pierces the aponeurotic covering of Hunter's canal, and descends 

 in company with the long saphenous nerve between the sartorius 

 and gracilis, where it lies beneath the fascia lata. It subsequently 

 pierces that fascia, and enters the leg on its inner aspect, to be 

 distributed to the integument over the upper third. This branch 

 anastomoses with the inferior internal articular of the pop- 

 liteal. The dee-p branch at once enters the vastus internus, in 

 which it descends anterior to the tendon of the adductor magnus. 

 It gives branches to the vastus internus and crureus, and anasto- 

 moses with the superior internal articular of the popliteal. It also 

 furnishes a cross branch, which passes outwards in front of the femur 

 above the patellar siuface to form an arch with a branch of the 

 superior external articular of the popliteal. Additional anasto- 

 moses are formed with the long descending branch of the external 

 circiunfiex, and the lowest perforating branch of the arteria pro- 

 funda femoris. 



Varieties ol the Femoral Artery — I. The Trunk.-— (1) In rare cases the 

 femoral artery may be found on the back of the thigh in company with the 

 great sciatic nerve. In such cases the vessel is derived from the internal iliac, 

 and may be regarded as a large sciatic arterj'. Under these conditions the 

 external ihac artery ends as the arteria profunda femoris. 



(2) Occasionally the superficial femoral artery divides just below the origin 

 of the arteria profunda femoris into two branches of equal size, which descend 

 in close contact, and subsequently unite to form one trunk before reaching 

 the femoral opening in connection with the adductor magnus. 



n. The Branches — (i) Arteria Profunda Femoris. — In normal cases this 

 artery arises from the common femoral from i^ to 2 inches below Poupart's 

 Ugament. The common femoral arter>-, however, may di\4de into superficial 

 femoral and deep femoral at any point between this and Poupart's hgament. 

 The superficial and deep femoral arteries may even spring from the lower 

 part of the external iliac a httle above Poupart's Ugament, in which case two 

 large arteries would pass out beneath that Ugament, instead of one. More 

 rarely, the division of the common femoral into superficial and deep femoral 

 may take place lower down than the normal level, even as low as 4 inches below 

 Poupart's Ugament. 



(2) External Circumflex Artery. — This vessel is very Uable to variation. 

 It may arise from the common femoral instead of the deep femoral, as in cases 

 of low origin of the latter vessel, or it may arise in two branches, one from 

 the deep femoral and one from the common femoral, or both from the deep 

 femoral, or both from the common femoral. 



(3) Internal Circumflex Artery. — This vessel is not so Uable to variation 

 as the external circumflex. It may arise along \\ith the external circumflex ; 

 it may spring from the common femoral ; it may be a branch of the deep 

 epigastric ; or it may be derived from the external iliac. 



In cases of low origin of the deep femoral, the external and the internal 

 circumflex arteries usuaUy spring from the common femoral. 



(4) Arteria Anastomotica Magna. — In very rare cases the superficial branch 

 of this artery assumes considerable length, and, under the name of the internal 

 saphenous artery, accompanies the internal saphenous vein down the inner 

 side of the leg as far as the internal malleolus. 



Unusual Branches. — The deep epigastric, the deep circumflex iUac, or 

 an abnormal obturator arter^', may arise from the common femoral near 

 Poupart's ligament. 



Collateral Circulation after Occlusion of the Femoral Artery. — i. The Common 

 Femoral Artery. — (a) The superficial perineal and dorsaUs penis arteries, both 

 from the internal pudic of the internal iUac, anastomose ^^^th the superior and 

 inferior external pudics of the common femoral. 



