The Liver

The liver is relatively large, weighing usually about 5 per cent. of the body-weight. It is divided into six or seven lobes by fissures which converge at the portal fissure. When the gland is examined in the soft condition, all the lobes are visible on the visceral surface, but usually only four on the parietal surface.

The left lateral lobe is the largest, and is oval in outline. The left central lobe is much smaller and is prismatic. The right central lobe is second in size, and presents a somewhat tongue-shaped quadrate lobe, marked off by the deep fissure in which the gall-bladder lies. The right lateral lobe is third in size, and is oval in outline. On its visceral surface is the large caudate lobe; this consists of two parts—on the right, the caudate process; on the left, the papillary process or lobe, both often being subdivided by fissures.

When hardened in situ (with the stomach full), the gland presents the following characters:

The visceral surface is marked by a somewhat oblique ridge (corresponding to the lesser curvature of the stomach), which separates two deep cavities. The depression to the left of the ridge is occupied by the body and fundus of the stomach. The depression on the right is smaller, and is occupied by the pyloric part of the stomach, the origin of the duodenum, and the right branch of the pancreas. The gall-bladder is not visible.

When the stomach is empty and contracted, the visceral surface of the liver is strikingly different. There is then a shallow impression for the left part of the stomach on the left lobe, and a large convex area, related to the small intestine and a mass of omentum. The pyloric and duodenal impressions are not much changed. The gall-bladder is visible.

The portal fissure is very deep and might well be termed a fossa. It is bounded on the right (externally) by the caudate process, on the left (internally) by the papillary process or lobe, which is directed ventrally. The hepatic artery enters at the dorsal end and the portal vein centrally, while the bile-duct leaves at the ventral part. The left central lobe is not visible, and the right central one is largely concealed.

The parietal surface is extremely convex, being adapted to the diaphragm and the adjacent part of the ventral wall of the abdomen. On it all the lobes except the papillary are completely or partially visible. The gall-bladder is visible in the fissure between the quadrate and chief portions of the right central lobe.

The dorsal border presents a renal impression on its right portion. The posterior vena cava passes downward and forward at first in a deep groove on the caudate lobe, then largely embedded in the parietal surface of the right lateral lobe; it receives two large hepatic veins just before piercing the diaphragm.

The œsophageal notch is large, and is occupied on the right by the thick margin of the hiatus œsophageus. The left border is opposite to the ninth and tenth ribs; it is thin and is marked by numerous indentations. The caudate process extends usually a little beyond the last right rib, between the right kidney and the right branch of the pancreas. The ventral border lies on the ventral abdominal wall a variable distance behind the xiphoid cartilage.

The gall-bladder lies in the fossa vesicæ felleæ, between the two parts of the right central lobe; it does not reach to the ventral border of the liver. The cystic duct joins the hepatic duct at the lower part of the portal fissure, forming with it the bile duct (Ductus choledochus); the latter passes to the right and opens into the duodenum, about two or three inches (ca. 5 to 8 cm.) from the pylorus.

Of the ligaments, the coronary and right lateral are well developed, but the left lateral and falciform are small.