SITUS VISCERUM. 471 



3. Internal organs of generation. 



a. Prostata surrounds the collum vesicce and the commence- 

 ment of the urethra, situated close before the vesicul. seminal. 

 and vasa deferent., above the perinceum and the lower extremity 

 of rectum ; its anterior pointed extremity behind and below the 

 lig. arcuatum. 



b. Vesiculce seminales are placed close together, behind and 

 above the prostata, between rectum and fundus vesicce, before and 

 external to the ureters and vasa deferentia. 



c. Vas deferens, passes on either side through the internal in- 

 guinal ring into the abdominal cavity, bends round art. epigastrica 

 and over vasa cruralia backwards, inwards, and downwards, lying 

 at first at the side, then on the fundus of the urinary bladder, be- 

 fore the ureter, and internal to the vesic. seminal, of its own 

 side. 



d. Vagina, between rectum and bladder, below the fundus 

 vesicce and urethra, in the axis of the lesser' pelvis. 



4. Rectum : it lies on the posterior wall of the pelvis from the 

 promontorium down to the end of the coccyx ; in women, behind 

 uterus and vagina ; in men, behind and below the prostate, blad- 

 der, vesiculce seminales, and vasa deferentia. Its most superior 

 portion is covered in front, and laterally by the peritoneum. 



5. Vessels : 



a. Aorta abdominalis descends through hiatus aorticus into the 

 abdomen, lies close to the anterior surface of the lumbar vertebrae 

 (as far as the cartilage between the fourth and fifth), to the left of 

 ven. cava infer., behind the cardia, caput pancreat., third portion 

 of duodenum, radix mesenterii. Its branches : 



1. Phrenicce inferr. a ndc&Ziaca, arise close under hiatus aorticus. 



2. Lumbares I., mesenterica super., arise before the twelfth dor- 

 sal vertebra. 



3. Supra renales, renales, spcrmaticce intern. Lumbares II., 

 before the second lumbar. 



4. Lumbares III., arise before the third lumbar. 



5. Mesenterica inferior, between third and fourth lumbar. 



6. Lumbares IV., before \\\Q fourth lumbar. 



7. Sacra media and iliacce, between fourth andffth lumbar. 



b. Artt. iliacce communes descend obliquely from the place of 

 division of the aorta outwards and backwards behind the ureters, 

 on the inner side of m. psoas, as far as symphys. sacro-iliaca. 

 The left lies immediately before the vena iliaca sinistra on the 

 outside, the right goes first over v. iliaca sinist., and then passes 

 to the inner side of v. iliaca dextra. Their branches : 



