346 



INFERIOR VENA CAVA. 



Fig. 165.* The Internal iliac vein is formed by vessels 



which correspond with the branches of the in- 

 ternal iliac artery ; it receives the returning 

 blood from the gluteal, ischiatic, internal pudic, 

 and obturator veins, externally to the pelvis ; 

 and from the vesical and uterine plexuses 

 within the pelvis. The vein lies to the inner 

 side of the internal iliac artery, and terminates 

 by uniting with the external iliac vein, to form 

 the common iliac. 



The Vesical and prostatic plexus is an im- 

 portant plexus of veins which surrounds the 

 neck and base of the bladder and prostate 

 gland, and receives its blood from the great 

 dorsal vein of the penis, and from the veins of 

 the external organs of generation. It is retain- 

 ed in connection with the sides of the bladder 

 by a reflexion of the pelvic fascia. 



The Uterine plexus is situated around the 

 vagina, and upon the sides of the uterus, be- 

 tween the two layers of the broad ligaments. 

 The veins forming the vesical and uterine 

 plexus are peculiarly 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 com- 

 mon iliac, shorter than the left, ascends ob- 

 liquely behind the corresponding 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 com- 

 mon iliac artery, near its origin, to unite with the right vein in the forma- 

 tion of the inferior vena cava. The right common iliac vein has no branch 

 opening 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 lam- 



* The veins of the trunk and neck. 1. The superior vena cava. 2. The left vena 

 innominata. 3. The right vena irmominata. 4. The right subclavian vein. 5. The 

 internal jugular vein. 0. The external jugular. 7. The anterior jugular. 8. The infe- 

 rior vena cava. 9. The external iliac vein. 10. The internal iliac vein. 11. The com- 

 mon iliac veins; the small vein between these is the vena sacra media. 12, 12. Lum- 

 bar 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, commencing inferiorly in the lumbar veins. 18. The lesser ^ena 

 azygos, also commencing 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 a/ygos, 

 oiid terminating superiorly in the left vena innominata. 



