ABDOMEN AND PELVIS 489 



and study its internal structure. Examine the aggregated nod- 

 ules of the vermiform process (noduli lymphatici aggregati pro- 

 cessus vermiformis). Good specimens for study can be made 

 by blowing up the caecum and lower part of the colon ascendens ; 

 when dry, windows can be cut out to expose the interior. 



Structures in the Omentum Minus. (See Fig. 258.) 



Elevate the anterior margin of the liver and stitch it to the 

 lower margin of the thorax. Then remove, by blunt dissection, 

 the anterior layer of the hepatoduodenal ligament (lig amentum 

 hepatoduodenale) and study 



(a) Common bile-duet (ductus choledochus). 



Make frequent use of models to complete this study. 

 Dissect out carefully the duct, as far as its entrance into the 

 wall of the duodenum. What is its general direction? 

 Does the direction of the canal depend upon the form of 

 the duodenum? To what vertebra is it related above and 

 below ? 



Notice that the duct may be divided for descriptive pur- 

 poses into a duodenal, a pancreatic, and a parietal portion. 

 What is the course of the pancreatic division? Determine 

 accurately the relations of the duct to the vena cava infe- 

 rior, the fascia of Treitz, the termination of the V. mesen- 

 terica superior, the ductus accessorius and ductus pan- 

 creaticus. 



Now clean this duct towards the liver and examine 



(aa) Hepatic duct (ductus hepaticus). Notice the two biliary 



ducts passing from the porta hepatis and uniting to form 

 the hepatic duct. Determine their relation to other struct- 

 ures found here. Are any aberrant vessels of the liver 

 (vasa aberrantia hepatis) present? 



(ab) Cystic duct (ductus cysticus}. Determine its relation to the 



gall-bladder (vesica fellea). 



The study of this duct will be completed when the dis- 

 section of the liver is made. 



(b) Portal vein (vena portae). (Vide Spalteholz, Fig. 498.) 



Exercise great care in cleaning this vein. Free the pan- 

 creas from the posterior abdominal wall; disturb its rela- 

 tions as little as possible. Determine the relation of the 

 portal vein to the head of the pancreas and the first or 

 superior portion of the duodenum (pars superior duodeni). 

 Supplement dissection by use of models. Examine the fol- 

 lowing tributaries: 



(ba) Coronary vein of stomach (V. coronaria ventriculi). 



(bb) Superior mesenteric vein (V. mesenterica superior), 

 (be) Inferior mesenteric vein (V. mesenlcrn-n inferior}. 



The tributaries of the last two veins have been studied in 

 the earlier dissection. 



