314 



SPERMATIC ARTERIES. 



The Colica dextra arises from about the middle of the concavity of the 

 superior mesenteric, and divides into branches which form arches, and are 

 distributed to the ascending colon. Its descending branches inosculate 

 with the ileo-colica, and the ascending with the colica media. 



The Colica media arises from the upper part of the concavity of the su- 

 perior mesenteric, and passes forwards between the layers of the transverse 

 mesocolon, where it forms arches, arid is distributed to the transverse 

 colon. It inosculates on the right with the colica dextra ; and on the left 

 with the colica sinistra, a branch of the inferior mesenteric artery. 



The SPERMATIC ARTERIES are two small vessels which arise from the 

 front of the aorta below the superior mesenteric ; from this origin each 

 artery passes obliquely outwards, and accompanies the corresponding 

 ureter along the front of the psoas muscle to the border of the pelvis, 

 where it is in relation with the external iliac artery. It is then directed 

 outwards to the internal abdominal ring, and follows the course of th* 



Fig. 1 55 



The distribution and branches of the inferior mesenteric artery. 1, 1. The superior 

 mesenteric artery, with its branches and the small intestines turned over to the right 

 side. 2. The caecui. and appendix coeci. 3. The ascending colon. 4. The transverse 

 colon raised upwards. 5. The descending colon. 6. Its sigmoid flexure. 7. The rec- 

 tum. 8. The aorta. 9. The inferior mesenteric artery. 10. The colica sinistra, inos- 

 culating with, 11, the colica media, a branch of the superior mesenteric artery. 12, 12 

 Sigmoid branches. 13. The superior hsmorrhoidal artery. 14. The pancreas. 15. 

 The descending portion of the duodenum. 



