272 THE RABBIT 



Second Day 



The Alimentary System and Vascular Systeva (part). 



Free the alimentary system from the abdominal cavity, by severing as much 

 as possible of the mesenteric attachment without damaging the veins, and 

 arteries supplying the canal. Leave the duodenal loop intact. Make out the 

 following parts : — 



(a) The liver, composed of five lobes, with the gall-bladder embedded in the 



right central lobe. 



(b) The stomach, following the gullet or oesophagus and partly covered by 



the liver. The dilated anterior or left end of the stomach is the 

 cardiac end, the narrower posterior or right end is the pyloric end. 



(c) The spleen, a dark red body behind the stomach and attached to the 



cardiac end. 



{d) The duodenum, the first portion of the small intestine, extending from 

 the pyloric end of the stomach along the right side of the abdomen, 

 and forming a U-shaped loop. 



(e) The pancreas, a diffuse gland, consisting of a number of lobules like 

 masses of fat, and spread out in the mesentery which connects the 

 two limbs of the duodenum. The pancreatic duct, receiving smaller 

 ducts, and opening into the distal limb of the duodenum (inner side) 

 about two inches from the bend. 



(/) The ileum (main portion of small intestine), following the duodemun. 

 It is much-coiled and very long (about seven feet). 



(g) The sacculus rotundus, the dilated end of the ileum. 



(h) The caecum, the first portion of the large intestine, into which the 

 sacculus rotundus opens. The caecum is a wide tube marked by a 

 winding spiral constriction. It ends blindly in a finger-shaped pro- 

 cess, the vermiform appendix, and proximally it is continuous with 

 the colon. 



(i) The sacculated colon, which is a continuation of the caecum. 



(j) The long and narrow rectum, which follows the colon and terminates in 

 the anus. The faecal pellets within the rectum give it a moniliform 

 appearance. 



(k) The bladder, opening to the exterior by the tirino-genital opening. 



AT^.^B.— The mesentery is often infested with small semi-transparent sac-like 

 bodies; these are " bladder- worms " of the common dog tapewoi-m {Taenia 

 serrata). They may also be seen in the liver. 



Note the following veins and arteries in connection with the alimentary 

 canal : — 



(i) The portal vein {see page 270), which conveys the blood from the 

 alimentary canal and associated organs to the liver (hepatic portal 

 system), is formed by the union of the following veins : — 



{a) The posterior mesenteric, which collects the blood from the 

 posterior part of the rectum. 



