ANATOMY IN A NUTSHELL. 



455 



which numerous branches are given off to supply the mesentery and the small 

 intestine. Four or five sets of arches are given off. The ilio-colic artery 

 is given off from the right side of the superior mesentery artery. It passes be- 

 tween the layers of the mesentery to the right iliac fossa where it divides into 

 two -anehes, ascending and descending. The ascending one passes to the 

 ascending colon and anastomoses with the colica-dextra. The descending one 

 passes to the lower part of the ileum, csecum. appendix, and ileo-csecal valve. 

 The colica-dextra arises from the middle of the superior mesentery artery 

 and passes behind the peritoneum to the ascending ion where it gives off an 

 ascending branch which anastomoses with the colica-media. and a descending 

 branch which anastomoses with the ileo-colic. Colica-media comes from the 

 upper part of the concavity of the superior mesenteric artery and passes for- 



PLATE CCXLIIL 



LESSER WING. 



1 - ANT.CLINOIO 

 PROCESS 



2 - MID. CLINOIO 



PROC 



3 - POSTCLINOID PROC 

 4 -OPTIC GROOVE 

 5-- OLIVARY PROC. 



6 - SELLA TURCICA. 



7 - CAVERNOUS GROOVE 

 8-LINGULA 

 9 -SPINOUS PROC. 



\/\ SUPP0RT5 

 PTERYGOI 



GRqOVE FOR OLFACTORY TRACT. C REATER WING 



10- FORAMEN 



OPTICUM. 



II- GROOVE FOR 



SIXTH WTRVE. 



12 -SPHENOIDAL 

 FISSURE. 

 13- FORAMEN 



VESALII. 

 H- FORAMEN OVALE 

 15- FORAMEN 



'X-'l SPINOSUM. 



1/ 16- FORAMEN ROruNDUM 



Posterior View of the Sphenoid Bom:. 



ward in the transverse meso-colon where it givi s a right branch which anas- 

 tomoses with the colica-dextra, and a left branch which anastomoses with the 

 colica-sinistra. ((') (Plate CLVII.) The inferior mesentery artery arises from 

 the left side of the aorta aboul an inch and a half above the bifurcation. It 

 supplies the descending colon, sigmoid flexure, and the greater part of the rec- 

 tum. It lies a1 hist on the left side of the abdominal aorta, then crosses the 

 Psoas muscle, left common iliac artery, ami un ter, to the back of the rectum. 

 It gives off the following branches. COLU \->i\i>ti; \. which passes behind the 

 peritoneum upward in front of the left kidney to th< descending colon where it 

 divides into an ascending branch, which anastomoses with the colica-media, 

 and a descending branch which anastomoses with the sigmoid artery and the 

 superior hemorrhoidal artery. Tin: sigmoid lrteri passes to the sigmoid 

 flexure and anastomosi s with the colica-sinisl ra and the superior haemorrhoidal. 



