248 



THE VASCULAR SYSTEM. 



(3) The dorso-lumbar vein ( J'eua dorso-lumhalis), (Fig. 1 63 a) is 

 a vein (or more usually several) arising" by twigs in the dorsal and 

 outer walls o£ the abdomen ; it joins the renal portal vein opposite 

 the kidney. 



(4) The oviducal veins (Fig. 163 ov) are irregular veins from 

 the oviducts^ which open either into the dorso-lumbar vein^ or into 

 the renal portal vein. 



b. The hepatic portal system. 



The liver receives blood from two sources : (i) from the hind- 

 limbs by means of the 

 '^' ^ ^' anterior abdominal 



vein^ and (2) from the 

 alimentary canal by 

 the hepatic j)ortal vein. 



The anterior ab- 

 dominal vein ( Vena 

 abdomhiaIis),{¥\gB. 159 

 ab, 164 Va) is formed, 

 a little in front of the 

 symphysis pubis, by 

 the union of the two 

 pelvic veins. It courses 

 forwards along the 

 middle line of the 

 ventral body-wall un- 

 til opposite the liver, 

 where it ascends and 

 divides into three 

 branches, of which 

 two enter the right 

 and left lobes of the 

 liver respectiveyl. The 

 third, the Bamtis de- 

 scendons, joins the 

 hepatic portal vein. 

 The anterior abdomi- 

 nal vein receives the 

 following veins : — 

 a. The vesical vein [Vena vesicalis), (Fig. 163 Vv) ; a median 

 vein arising in the groove between the lobes of the bladder from 

 lateral branches, which extend outwards on the bladder. This vein 



