INFERIOR VENA CAVA. 381 



The Uterine plexus is situated around the vagina, and upon the 

 sides of the uterus, between the two layers of the broad ligaments. 

 The veins forming the vesical and uterine plexus are very subject to 

 the production of phlebolites. 



The Common iliac veins are formed by the union of the external 

 and internal iliac vein on each side of the pelvis. The right common 

 iliac, shorter than the left, ascends obliquely behind the correspond- 

 ing artery ; and upon the intervertebral substance between the fourth 

 and fifth lumbar vertebrae, unites with the vein of the opposite side, 

 to form the inferior cava. The left common iliac, longer and more 

 oblique than the right, ascends behind, and a little internally to the 

 corresponding artery, and passes beneath the right common iliac artery, 

 near its origin, to unite with the right vein in the formation of the 

 inferior vena cava. The right common iliac vein has no branch open- 

 ing into it ; the left receives the vena sacra media. These veins have 

 no valves. 



INFERIOR VENA CAVA. 



The inferior vena cava is formed by the union of the two common 

 iliac veins, upon the intervertebral substance between the fourth and 

 fifth lumbar vertebra. It ascends along the front of the vertebral 

 column, on the right side of the abdominal aorta, and passing through 

 the fissure in the posterior border of the liver and the quadrilateral 

 opening in the tendinous centre of the diaphragm, terminates in the 

 inferior and posterior part of the right auricle. There are no valves 

 in this vein. 



It is in relation from below upwards, in front with the mesentery 

 transverse duodenum, portal vein, pancreas, and liver, which latter 

 nearly and sometimes completely surrounds it ; behind it rests upon the 

 vertebral column and right crus of the diaphragm, from which it is se- 

 parated by the right renal and lumbar arteries ; to the right it has the 

 peritoneum and sympathetic nerve ; and to the left the aorta. 



The Brandies which the inferior cava receives in its course, are 

 the 



Lumbar, 



Right spermatic, 



Renal, 



Supra-renal, 



Phrenic, 



Hepatic. 



ternal iliac vein. 11. The common iliac veins ; the small vein between these is 

 the vena sacra media. 12, 12. Lumbar veins. 13. The right spermatic vein. 

 14. The left spermatic, opening into the left renal vein. 15. The right renal 

 vein. 16. The trunk of the hepatic veins. 17- The greater vena azygos, com- 

 mencing inferiorly in the lumbar veins. 18. The lesser vena azygosj! also com- 

 mencing in the lumbar veins. 19. A branch of communication with the left 

 renal vein. 20. The termination of the lesser in the greater vena azygos. 21 . 

 The superior intercostal vein ; communicating inferiorly with the lesser vena 

 azygos, and terminating superiorly in the left vena innominata. 



