ANGIOLOGY 251 



veins of the abdominal cavity have many anastomoses forming 

 many arcs, making possible two outlets for the blood. 



The azygos sacralis empties into the arcus at about its middle. 

 From here it extends forward to the inside and under the kidney and 

 empties into the vena suprarenalis externa. 



The vena cutanea pubica originates on the lower portion of the 

 abdomen, collects the blood from the muscles of the distal part of 

 the ischium, and enters the pelvic cavity between the ischium and 

 the ilium. It joins with the vena cutanea caudalis. 



The vena cutanea caudalis originates from branches which drain 

 the skin and other parts of the ventral coccygeal region. The vena 

 cutanea pubica also communicates with the vena caudalis muscularis 

 and with the vena pudenda, thus forming the caudal trunk of the 

 vena hypogastrica. 



The vena pudenda originates in the walls of the cloaca in the 

 region of the generative organs. 



A small vena spermatica accompanies the lower end of the vas 

 deferens and the ureter, and empties medially into the vena pudenda. 



The pars renalis of the vena hypogastrica extends from the middle 

 of the arcus to the union of the vena hypogastrica and the vena 

 cruralis. 



The vena hypogastrica communicates with the pars renalis. 

 The vessels that empty into the pars renalis are as follows: 



The venae sacrales collect blood from the dorsal wall of the 

 abdominal cavity and enter the pelvis through the foramen sacralis. 

 They pass between the pelvic wall and kidney, and at times pass 

 through the kidney tissue. They empty into the pars renalis of the 

 hypogastric arch. 



The venae intervertebrales sacrales (Fig. 72, No. 2) originate 

 in the region of the roots of the plexus of sacral nerves and pass 

 through the kidney substance or on the dorsal surface and empty into 

 the pars renalis. 



The venae renales (Fig. 72, No. i) are very numerous and origi- 

 nate in the kidney substance, forming two main and several minor 

 branches, which pass posteriorly, and empty partly into the vena 

 hypogastrica, partly into the vena renalis magna, and also into the 

 vena intervertebralis; other branches empty into the trunk of the 

 iliaca communis. 



The vena suprarenalis externa (Fig. 70, No. 30) is located near 

 the anterior rim of the kidney and is connected with the vena 



