100 VENOUS CIRCULATION. 



dorsum of the foot, the latter upon 

 the internal and plantar portion. 

 After free anastomosis, the external 

 ascends upon the outer side of the 

 leg and terminates in the popliteal, 

 while the internal runs up on the 

 inner side of the leg and thigh, and 

 ends in the femoral vein, a short dis- 

 tance below Poupart's ligament. 



The deep-seated veins have all 

 the same course, and the same' name 

 with the arteries they accompany ; 

 every artery except the larger trunks 

 having two veins called the venas 

 comites. Hence we follow the veins 

 attending the anterior and posterior 

 tibial arteries, with the peroneal, 

 ascending the leg and by their com- 

 mon junction at the posterior part 

 of the knee joint, forming the popli- 

 teal vein. The popliteal vein takes 

 the same course as the artery, to 

 the tendon of the adductor magnus, 

 where it becomes femoral. It now 

 ascends to Poupart's ligament, along with the artery, and 

 upon its inner side at the upper part of the thigh, where it 

 becomes the external iliac vein, this unites with the internal 

 iliac vein from the interior of the pelvis, forming the com- 

 mon iliac veins on either side, which at the fourth lumbar 

 vertebra unite together and constitute the inferior cava, or 



FIG. 9 represents the trunks and principal branches of the venous system. 

 1 Descending vena cava. 2 Left vena innominata. 3 Right vena innomina- 

 ta. 4 Right subclavian vein. 5 Internal jugular vein. 6 External jugular. 

 7 Anterior jugular. 8 Inferior vena cava. 9 External iliac vein. 10 In- 

 ternal iliac. 11 Primitive iliac. 12 Lumbar veins. 13 Right spermatic. 

 14 Left spermatic vein. 15 Right emulgent vein. 16 Trunk of hepatic 

 veins. 17 Vena azygos. 18 Hemi-azygos. 19 Communicating with left 

 renal vein. 20 Union of hemi-azygos with vena azygos. 21 Superior inter- 

 costal vein. 



