VEINS. 



Fig. 311. The Internal or 

 Long Saphenous Vein and its 

 Branches. 



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The internal saphenous vein (Fig. 311) commences 

 from a minute plexus, which covers the dorsum and 

 inner side of the foot ; it ascends in front of the inner 

 ankle, and along the inner side of the leg, behind 

 the inner margin of the tibia, accompanied by the 

 internal saphenous nerve. At the knee, it passes 

 backwards behind the inner condyle of the femur, 

 ascends along the inside of the thigh, and, passing 

 through the saphenous opening in the fascia lata, 

 terminates in the femoral vein about an inch and a 

 half below Poupart's ligament. This vein receives 

 in its course cutaneous branches from the leg and 

 thigh, and at the saphenous opening, the superficial 

 epigastric, superficial circumflex iliac, and external 

 pudic veins. The veins from the inner and back 

 part of the thigh frequently unite to form a large 

 vessel, which enters the main trunk near the saphe- 

 nous opening; and sometimes those on the outer 

 side of the thigh join to form a large branch; so that 

 occasionally three large veins are seen converging 

 from different parts of the thigh towards the saphe- 

 nous opening. The internal saphenous vein com- 

 municates in the foot with the internal plantar vein; 

 in the leg, with the posterior tibial veins, by branches 

 which perforate the tibial origin of the Soleus mus- 

 cle, and also with the anterior tibial veins ; at the 

 knee, with the articular veins; in the thigh, with 

 the femoral vein by one or more branches. The 

 valves in this vein vary from two to six in number; 

 they are more numerous in the thigh than in the leg. 



The external or short saphenous vein (Fig. 312) is 

 formed by branches which collect the blood from 

 the dorsum and outer side of the foot ; it ascends 

 behind the outer ankle, and along the outer border 

 of the tendo Achillis, across which it passes at an 

 acute angle to reach the middle line of the posterior 

 aspect of the leg. Passing directly upwards, it per 

 forates the deep fascia in the lower part of the pop- 

 liteal space, and terminates in the popliteal vein, 

 between the heads of the Gastrocnemius muscle. It 

 is accompanied by the external saphenous nerve. It 

 receives numerous large branches from the back part 

 of the leg, and communicates with the deep veins on 

 the dorsum of the foot, and behind the outer malleo- 

 lus. This vein has only two valves, one of which is 

 al ways found near its termination in the popliteal vein. 



The Deep Veins of the lower extremity accom- 

 pany the arteries and their branches, and are called 

 the vense comites of those vessels. 



The external and internal plantar veins unite to 

 form the posterior tibial. They accompany the pos- 

 terior tibial artery, and are joined by the peroneal 



veins. 



The anterior tilial veins are formed by a continuation upwards of the venra 

 cornites of the dorsalis pedis artery. They perforate the interosseous membrane 

 at the upper part of the leg, and form, by their junction with the posterior 

 l, the popliteal vein. 





