ABDOMEN. 255 



which these structures were bound together by connective tissue. This connec- 

 tive tissue is the capsule of Glisson the framework for the hepatic root-struc- 

 tures. 



Hepatic Nerves and Arteries. The nerves reach the liver through the 

 transverse fissure, are protected in transit by the capsule of Glisson, are dis- 

 tributed to the substance of the liver on the branches of the portal vein and 

 hepatic artery. These nerves come from the hepatic plexus, one of the divi- 

 sions of the coeliac plexus. This plexus is made up of branches from the 

 sympathetic, the right phrenic, and the left pneumogastric or vagus nerve. The 

 nutrient artery to the liver is the hepatic. The liver receives blood for purifica- 

 tion from all the other abdominal organs of digestion, through the portal vein ; 

 all the blood in the liver escapes by the hepatic veins into the vena cava. To find 

 these veins, turn the liver clown into its normal position, locate the emergence of 

 the vena cava from the abdominal cavity through the diaphragm, and into the 

 pericardium. Now cut through the diaphragm at this point and plow through 

 liver substance, and you will find the hepatic veins. Another method is this : 

 having located the vena cava above the diaphragm, cut a hole in its walls and 

 follow the vessel downward until you see its hepatic tributaries. 



Foetal Remains. These are the round ligament and the ductus venosus. 

 The former is the connective-tissue remnant of the umbilical vein, that in the 

 foetus brought pure blood from the placenta. (Fig. 155.) This vein, on reaching 

 the liver, broke up into three channels : (i) The greater part of the blood 

 joined the portal vein and traversed the liver ; (2) a small amount entered the 

 left lobe ; (3) a small quantity passed through a vessel the ductus venosus to 

 meet the left hepatic vein, as that vessel was entering the vena cava. After the 

 lungs became the organ of respiration, the placental circulation lost its specific 

 character as a conduit, t The main vessel, the umbilical vein, dwindled to a mere 

 cord the round ligament. The three termini of the vein did the same, and are 

 known as remnants. The ductus venosus dwindled, and is consequently in the 

 adult a fcetal remnant. 



The portal vein in its relation to the root-structures of the liver will be seen 

 in figure 177. In your dissection you have found it embedded in Glisson's cap- 

 sule, and occupying a place between the hepatic artery and common bile duct, 

 and posterior to both. Its tributaries come from all the organs in the abdominal 

 cavity associated, with the digestion of food, except the liver. The veins which 

 you must demonstrate on your dissection as forming the portal vein are : (i) The 

 superior mesenteric ; (2) the inferior mesenteric ; (3) the splenic ; (4) the 

 gastric. Notice particularly on your dissection that three veins the gastric, 

 splenic, and superior mesenteric come together to form the portal vein directly ; 

 the inferior mesenteric is tributary to the splenic, hence it is not a primary, but a 

 secondary tributary to the portal vein. 



The hepatic veins must be located according to the two methods given under 

 caption of Hepatic Nerves and Arteries. (Page 253.) Having found the hepatic 

 vein, look on its under surface for "the remains of the ductus venosus, for, you 

 will remember, one branch of the umbilical vein in the foetus terminated here. 



(Fig. I55-) 



The gall-bladder and its system of ducts must now be carefully dissected. 

 Any degree of rough manipulation will defeat a perfect dissection. Follow these 

 steps : (i) Take the organ in the left hand, and with your forceps in your right 

 carefully dissect the connective tissue, holding the gall-bladder in the cystic 

 fissure. (2) Having now liberated the organ from its bed, and having exercised 

 every care not to injure the vessels and ducts attached thereto, you may (3) cut 

 a slit in the fundus of the organ, introduce a blowpipe, and inflate. (4) Have an 

 assistant ligate as you inflate. (5) Now follow downward, and liberate from the 



