LOBES AND FISSURES OF LIVER. 467 



On following outwards the left branch of the vena portee to the longi- 

 tudinal or antero-posterior fissure, it will be found united anteriorly with 

 the round ligament or the remains of the umbilical vein, and posteriorly 

 with the fine fibrous remnant of the ductus venosus. 



The liver is of a red-brown color and firm consistence ; and weighs 

 commonly in the adult from three to four pounds (fifty to sixty ounces). 

 Transversely the gland measures from ten to twelve inches ; from front to 

 back between six and seven inches; and in thickness, at the right end, 

 about three inches ; but this last measurement varies with the spot ex- 

 amined. 



In shape the liver is somewhat square. It has many named parts, viz., 

 two surfaces, two borders, and two extremities ; and the under surface is 

 further marked by lobes and fossa?, and by fissures which contain vessels. 



The connections and the ligaments of the liver are described at p. 434 

 and p. 438. 



Surfaces, On the upper aspect the liver is convex : extending from 

 front to back in the suspensory ligament, which divides the upper surface 

 into two unequal parts, of which the right is the larger. The under sur- 

 face is rendered irregular by lobes, fissures, and fossa? : in contact with it 

 is the gall-bladder; and a longitudinal sulcus divides it into a right and a 

 left lobe. 



Borders. The anterior border is thin, and is marked by two notches : 

 one is opposite the longitudinal sulcus on the under surface before alluded 

 to, and the other is over the large end of the gall-bladder. The posterior 

 border is much thicker at the right than at the left end ; and at the thick- 

 ened part it touches the right kidney and the diaphragm. Opposite the 

 vertebral column is a hollow in this border ; and the vena cava is partly 

 imbedded in it on the right of the spine. 



Extremities. The right extremity is thick and rounded; and the left 

 is thin and flattened. 



Lobes. On the under surface the liver is divided primarily into two 

 lobes, a right and a left, by the antero-posterior or longitudinal fissure ; 

 and occupying this surface of the right lobe are three others, viz., the 

 square, the Spigelian, and the caudate lobe : 



The left lobe, B, is smaller and thinner than the right, and there is a 

 slight depression inferiorly where it touches the stomach. 



The right lobe, A, forms the greater part of the liver, and is separated 

 from the left by the longitudinal fissure on the one aspect, and by the sus- 

 pensory ligament on the other. To it the gall-bladder is attached below ; 

 and the following lobes are projections on its under surface : 



The square lobe, c (lobulus quadratus), is situate between the gall- 

 bladder and the longitudinal fissure. It reaches anteriorly to the margin 

 of the liver, and posteriorly to the fissure (transverse) by which the ves- 

 sels enter the interior of the viscus. 



The Spigelian lobe, D, lies behind the transverse fissure, and forms a 

 roundish projection on the surface. On its left side is the longitudinal 

 fissure; and on its right, the vena cava inferior. 



The caudate lobe, E, is a slight, elongated eminence, which is directed 

 from the Spigelian lobe behind the transverse fissure, so as to form the 

 posterior boundary of that sulcus. Where the fissure terminates this pro- 

 jection subsides in the right lobe. 



Fissures. Extending horizontally half across the right part of the liver 

 between the Spigelian and caudate lobes on the one hand, and the square 



