POPLITEAL ARTERY. 441 



internal articular arteries, and with the recurrent branch of the anterior 

 tibial artery. 



(a) A superficial branch accompanies the saphenous nerve beneath the sartorius 

 muscle to the integument on the inner side of the knee. 



(b) The external branch, arising from the lower part of the vessel, crosses over the 

 femur, supplies offsets to the knee-joint, and forms an arch a little above the articular 

 surface, by anastomosing with the superior external articular artery. 



PECULIARITIES OP THE FEMORAL ARTERY AND BRANCHES. Trunk. Four instances 

 have been recorded of division of the femoral artery below the origin of the profunda 

 into two vessels, which subsequently were reunited near the opening of the adductor 

 magnus so as to form a single popliteal artery. In all these cases, the arrangement 

 of the vessels appears to have been similar. To one of them (that first observed) 

 special interest is attached, inasmuch as it was met with in a patient operated upon 

 for popliteal aneurism. (This case was treated by Charles Bell, and recorded in " The 

 London Medical and Physical Journal," vol. IvL p. 134. London, 1826.) 



The femoral artery is occasionally replaced at the back of the thigh by a trunk 

 continuous with the internal iliac. Having passed from the pelvis through the 

 large sacro-sciatic notch, this trunk accompanies the great sciatic nerve along the 

 back of the thigh to the popliteal space, where its connections and termination become 

 similar to those of the vessel presenting the usual arrangement. Four examples of 

 this deviation from the common state of the blood-vessel have been recorded. Refe- 

 rence is made to these in a Paper in vol. 36 of the Medico-Chirurgical Transactions, 

 giving an account of a specimen of remarkable deformity of the lower limbs of a 

 man in whom the artery was so transposed on both sides. 



Branches. The deep femoral is occasionally given off from the inner side of the 

 parent trunk, and more rarely from the back part of the vessel. Occasionally it 

 arises at a distance of less than an inch, and sometimes of more than two inches, 

 below Poupart's ligament. It was even found by Richard Quain arising, in one 

 instance, above Poupart's ligament, and in another four inches below it ; but in the 

 latter instance the internal and external circumflex arteries did not arise from the 

 profunda. 



The external circumflex branch sometimes arises directly from the femoral artery ; 

 or it may be represented by two branches, of which, in most cases, one proceeds from 

 the femoral, and one from the deep femoral : both branches, however, have been 

 seen to arise from the deep femoral, and much more rarely, both from the femoral 

 artery. 



The internal circumflex branch may be transferred'to the femoral artery above the 

 origin of the profunda. Examples have also been met with in which the internal 

 circumflex arose from the epigastric, from the circumflex iliac, or from the external 

 iliac artery. 



POPLITEAL ARTERY. 



The popliteal artery, placed at the back of the knee-joint, extends along 

 the lower third of the thigh and the upper part of the leg, reaching from the 

 opening in the great adductor to the lower border of the popliteus muscle. 

 It is continuous above with the femoral, and divides at the lower end into 

 the anterior and posterior tibial arteries. 



This artery at first inclines from the inner side of the limb to reach a 

 point behind the middle of the knee-joint, and thence continues to descend 

 vertically to its lower end. Lyiug deeply in its whole course, it is covered 

 for some distance at its upper end by the semimembranosus muscle ; a little 

 above the knee it is placed in the popliteal space ; interiorly it is covered 

 for a considerable distance by the gastrocnemius muscle ; and at its termi- 

 nation by the upper margin of the soleus muscle. 



At first the artery lies close to the inner side of the femur ; in descending, 



