538 



THE VEINS OF THE LOWER LIMB. 



inner and back parts of the thigh, and opening into the saphenous vein a little below 

 its aperture in the fascia lata. 



The valves of the internal saphenous vein vary greatly in number (from 7 to 20), position, 

 and development. Two are often found near the termination of the vein, one just before, and 

 the other after it perforates the cribriform fascia in the saphenous opening ; but either or both 

 of these may be imperfect or absent. The proportion of competent valves diminishes with 

 age. (K. Klotz, "Untersuchungen uber die Vena saphena magna beim Menschen, besonders 

 rucksichtlich ihrer Klappenverhaltnisse," Arch. f. Anat., 1887 ; W. H. Bennett, " On Varicose 

 Veins of the Lower Extremities," 1889.) 



The external or short saphenous vein, smaller than the internal, proceeds 

 from the outer end of the arch on the dorsum of the foot. It passes behind the 

 outer ankle, and ascends in the leg along the outer border of the tendo Achillis, in 



Fig. 414. THE EXTERNAL SAPHENOQS VEIN. 



The vein, commencing on the dorsum and outer side of the foot, is seen 

 to pass up behind the outer ankle and to dip beneath the fascia in the popliteal 



company with the external saphenous nerve, and then over the 

 interval between the heads of the gastrocnemius to the lower 

 part of the popliteal space, where it perforates the deep fascia to 

 end in the popliteal vein. Opposite the ankle and along the leg 

 it communicates with the deep veins ; and it receives superficial 

 branches from the outer part of the foot and heel, and the back 

 of the leg, as well as one which descends on the posterior surface 

 of the thigh. A communicating branch usually passes from 

 this vessel near its termination upwards and forwards to the 

 internal saphenous vein ; and sometimes the trunk itself follows 

 this course, having no connection, or only a very small one, 

 with the popliteal vein. 



The number of valves in the external saphenous vein varies from 

 nine to thirteen (Houze). 



Varieties. The external saphenous vein, or a communicating 

 branch, is occasionally continued upwards behind the adductor magnus 

 to open into one of the perforating veins of the profunda. It has 

 also been seen ascending, wholly or in part, along the back of the thigh 

 to join the sciatic vein (ITyrtl, Hochstetter). According to Braune the 

 ending of the external saphenous vein is always double. 



DEEP VEINS OF THE LOWER LIMB. 



The deep veins accompany the arteries and their branches, following exactly 

 their distribution. Those below the knee, being for the most part disposed in pairs, 

 and presenting the disposition described in the corresponding veins of the upper limb, 

 are named the venw comites of the vessels with which they are associated. The venae 

 comites of the arteries of the leg, namely, the anterior and posterior tibial veins 

 (the latter having previously received the peroneal), unite near the lower border of 

 the popliteus muscle, and form by their junction the popliteal vein. 1 



The popliteal vein, thus formed, receives smaller branches corresponding to the 

 articular and muscular arteries, and the larger branch named the external saphenous 

 vein. In its course upwards the vein is placed superficially to the popliteal artery, 

 and it crosses that vessel gradually from the inner to the outer side. It passes with 



1 On the origin, communications, and valvular arrangements of these veins, see Braune and Muller, 

 op, clt. supra. 



