THE GREAT COLON 425 
Tt is somewhat difficult to get a correct idea of the cxcal orifices. The cecum is sharply 
curved here and a large fold projects into its interior, somewhat like a shelf, and separates the two 
orifices. The ileo-cxecal orifice faces chiefly dorsally, while the exco-colic orifice faces forward 
into the cecum. 
THE GREAT COLON 
The great colon (Colon crassum) begins at the cxco-colic orifice, and terminates 
by joining the small colon behind the saccus cecus of the stomach. It is ten to 
twelve feet (ca. 3 to 3.7 m.) long, and its average diameter (exclusive of its narrowest 
part) is about eight to ten inches (ca. 20 to 25 cm.). Its capacity is more than 
double that of the cecum. When removed from the abdomen, it consists of two 
parallel parts, which are connected by peritoneum and partially by areolar and 
muscular tissue also. Jn situ it is folded so that it consists of four parts, which are 
designated according to their position or numerically. The three bent connecting 
parts are termed the flexures. The first part, the right ventral colon (Colon ventrale 
dextrum), begins at the lesser curvature of the base of the cecum, about opposite 
the ventral part of the last rib or intercostal space.t_ It forms an initial curve, the 
Origin of small colon 
Pelvic mar taas 
flexure 
Diaphragmatic 
flexure 
SS Sternal 
flexure 
ee 
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Fic. 364.—Diacram or Cxcum snp Larce Coton or Horse. 
convexity of which is directed upward and backward; this part is in contact with 
the upper part of the right flank. It then passes downward and forward along the 
right costal arch and then along the floor of the abdomen.! Over the xiphoid 
cartilage it bends sharply to the left and backward, forming the sternal flexure 
(Flexura sternalis s. diaphragmatica ventralis). The second part, the left ventral 
colon (Colon ventrale sinistrum), passes backward on the abdominal floor, to the left 
of the first part and the cecum and, on reaching the pelvic inlet, bends sharply 
dorsally and forward, forming the pelvic flexure (Flexura pelvina). This is continued 
by the third part, the left dorsal colon (Colon dorsale sinistrum), which passes 
forward dorsal or lateral to the left ventral part, and on reaching the stomach, 
diaphragm, and left lobe of the liver, turns to the right, forming the diaphragmatic 
flexure (Flexura diaphragmatica dorsalis). The fourth part, the right dorsal colon 
(Colon dorsale dextrum), passes backward dorsal to the first part, and on reaching 
1 The position of the origin of the great colon is variable, and one may easily get a wrong 
pression on account of the peculiar arrangement of the bowel here. The colon usually presents 
saccular dilatation at the lesser curvature of the base of the caecum, which may be mistaken for 
its origin. The real origin is a constricted part or neck anterior to the sacculation. Thus the 
lon passes at first backward and then curves sharply downward and forward. Schmaltz has 
roposed the name “vestibulum coli’’ for this sacculation. 
