348 



DISSECTION OF THE ABDOMEN. 



longitudi- 

 nal 



(sub-divided 

 into two 

 parts), 



and one for 

 vena cava. 



Vessels in 

 the trans- 

 verse 

 lissure. 



Hepatic 

 duct. 



Hepatic 

 artery. 



Vena portse. 



Umbilical 

 vein in the 

 foetus ; 



condition 

 after birth. 



the liver. At the left end it is united at a right angle with the 

 longitudinal fissure. 



The longitudinal fissure extends from the front to the back of the 

 liver, between the right and left lobes ; that is, between the left lobe 

 and the quadrate in front and the Spigelian behind. In it, anterior 

 to the transverse fissure, lies the remnant of the umbilical vein (I t), 

 which is called the round ligament, and is oftentimes arched over 

 by a piece of the hepatic substance (pons hepatis) ; and behind that 

 fissure is a small fibrous cord, the remains of the vessel named the 

 ductus venosus in the foetus, which will be found running deeply in 

 the fissure between the Spigelian and the left lobe. In reference 

 to these structures the fore part of the longitudinal fissure is often 

 spoken of as the fissure for the round ligament, and the back part as the 

 fissure for the ductus venosus. 



The groove, or fissure for the vena cava is placed on the right side of 

 the Spigelian lobe, and is frequently bridged over by an extension 

 of the Spigelian to the right. If the cava (v c) be opened, two or 

 three large and some smaller hepatic veins will be observed 

 entering it. 



The groove which lodges the gall bladder is often inappropriately 

 called the fissure for the gall bladder. 



VESSELS IN THE TRANSVERSE FISSURE. The vessels in the 

 transverse fissure, viz., portal vein, hepatic artery and duct have 

 the following position : the duct in anterior, the portal vein 

 posterior, and the artery between the other two. 



The hepatic duct is formed by two branches, one from the right, 

 and one from the left lobe, which soon blend in a common tube. 

 After a distance of one inch and a half it is joined by the duct of the 

 gall-bladder ; and the union of the two gives rise to the common 

 bile-duct (b d). 



The hepatic artery (h a] is divided into two for the chief lobes, and 

 its branches are surrounded by nerves. 



The portal vein (p v) divides, like the artery, into two trunks for 

 the right and left lobes, and gives an offset to the Spigelian lobe ; 

 its left branch is the longer. 



Foetal condition of the umbilical vein. Before birth the umbilical 

 vein occupies the longitudinal fissure, and opens posteriorly into the 

 vena cava ; the portion of the vessel behind the transverse fissure 

 receives the name ductus venosus. Branches are supplied from it to 

 both lobes of the liver ; and a large one, directed to the right lobe, 

 is joined by the portal vein. Placental or purified blood courses 

 through the vessel at that period. 



Adult state. After birth the part of the umbilical vein in front of 

 the transverse fissure is closed, and becomes eventually the round 

 ligament or ligamentum teres. The ductus venosus is also obliterated, 

 only a thin cord remaining in its place. But the lateral branches 

 remain open, and subsequently form some of the divisions of the 

 portal vein. Occasionally the ductus venosus is found pervious for 

 some distance. 



