DISSECTION OF THE DOG 21 



right colic flexure (flexura coli dextra) ; (2) the second part of the colon, the 

 transverse colon (colon transversum) , hke the first, is generally very short. It 

 crosses the median plane immediately cranial to the root of the mesentery, and, 

 arriving on the left side of the abdomen, curves in a caudal direction at the left 

 colic flexure (flexura coli sinistra) ; (3) the descending colon (colon descendens) 



m. longissimus dorsi^ 



Vena cava caudalis 



Lymphoglandula 



m. iliO'Costaiis^ 



m. ohliquus 

 abdominis internus 



m. obliquui 

 abdominis e.rternus- 



m. transversus abdominis - 



Colon descendens^ 



Colon asomden. 



Fig. 6.- 



m. rectus abdominis-' 



-Transverse section through the abdomen on a level with the first lumbar 

 vertebra. Sections of smaU intestine are not named. 



forms by far the greater part of the whole tube. In order to expose it, it is neces- 

 sary to turn the mass of small intestine over to the right. The descending colon 

 wiU then be revealed to the left of the median plane in the form of a fairly 

 straight tube running towards the pelvis from the left cohc flexure. On approach- 

 ing the pelvis, a gradual slope towards the right causes the intestine to disappear 

 into the pelvic cavity about the middle Jine. In the female the colon gains the 

 pelvis by passing dorsal to the uterus ; in ths male, dorsal to the urinary bladder. 



\ o 3 



