Page:Laboratory Manual of the Anatomy of the Rat (Hunt 1924).djvu/92

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78
ANATOMY OF THE RAT

united anteriorly, and are in contact with the diaphragm. Posteriorly, the fissure extends upward, sometimes reaching the region of the inferior vena cava. The right lobule passes upward to the right of this vein, the left lobule to the left. The median lobe is fastened in this region to the vena cava. Very little, if any, hepatic glandular tissue connecting this lobe with the rest of the liver, is visible in a gross dissection.

The left lateral lobe is immediately behind and at the left of the median lobe of the liver. It attaches to the other lobes of the liver only at its dorsomedial angle, and here merely by its ducts, blood vessels, and connective tissue. The anterior surface is strongly convex, the posterior surface is concave and rests against the stomach and intestines. The lobe is thick near the center, tapering to a thin edge peripherally. The right side pushes in between the median and right lateral lobes.

The right lateral lobe lies behind and at the right of the median lobe. A vertical transverse cleft divides it into two almost completely separated lobules, one anterior, the other posterior. A bridge of hepatic tissue crossing the dorsal side of the inferior vena cava connects the two lobules with one another and with the caudate lobe on the left side of the abdomen. The posterior lobule is frequently annexed to the caudate lobe by a strip of hepatic glandular tissue crossing the ventral surface also of the inferior vena cava. Both lobules attach to the right surface of the vena cava. Aside from the glandular bridges mentioned above, a gross dissection fails to reveal connections of hepatic tissue with the other lobes of the liver. The anterior lobule is thick near the center, thinning out toward the sharp peripheral edges. Its convex anterior surface fits into a concavity near the right border of the median lobe. The right lateral surface rests against the diaphragm.