vi VEINS 85 



vein is formed by the confluence of two pelvic veins 

 (Fig. 2 1 , PV) , which can be traced along the base of the leg 

 (compare Fig. 3). Towards the front of the thigh is 

 the principal vein of the leg, the femoral vein (Fig. 21, 

 fnt), which on emerging from the leg, divides into two 

 branches. One of these is the pelvic vein already seen ; 

 it unites with the corresponding vessel of the opposite 

 side to form the abdominal vein (abd) . The other branch 

 of the femoral is called the renal portal vein (rn. pt) ; it 

 passes directly forwards, receiving the sciatic vein (sc) 

 from the back of the leg, and then goes along the outer 

 border of the kidney, finally branching out in that organ. 

 It also receives a large vein (ds. Imb) from the muscles 

 of the back. 



The abdominal vein receives, near its posterior end, 

 small veins (ves) from the urinary bladder. It passes 

 forwards, as already seen, receiving veins from the 

 abdominal muscles, and quite at its anterior end, a small 

 vein (cd) from the heart . It then divides into two branches 

 which enter the liver and branch out in that gland. 



The veins from the stomach (gs), the intestine (du, int), 

 spleen (spl) , and pancreas run in the mesentery alongside 

 the corresponding arteries. Near the li ver they all unite 

 to form a large vessel, the hepatic portal vein (hp. pt}, 

 which enters and branches out into the liver, first send- 

 ing off a branch which joins the abdominal. 



Thus the veins from all parts of the body, except the 

 lungs, ultimately discharge into the sinus venosus. The 

 veins from the lungs are quite singular in their course ; 

 they unite, in each lung, to form a single pulmonary vein 

 (Figs. 3 and 21, pnl), which passes dorsal to the sinus 

 venosus, and discharges, with its fellow of the opposite 

 side, into the left auricle. 



Character of the Blood in the Arteries and Veins. 

 There are certain differences between the arteries and 



