Liver Slides

The anatomical liver lobules are very easy to see in the pig liver because it contains a lot of connective tissue between lobules, as well as on the surface. Use it to become familiar with the various histologic features of the liver such as the portal triad, consisting of small branches of the portal vein, hepatic artery, and bile ductule. There may also be a smaller lymphatic vessel or two in the triad area, which are smaller than the blood vessels and contain no RBCs. Locate the central vein, sinusoids, and hepatocytes. Using the 43X objective you should be able to see small dark spots or threads between the hepatocytes, which are bile canaliculi. See demonstration.

The architecture of the liver can be described in 2 ways. Try to understand the relationship between the anatomical and functional lobules. The anatomical lobule with the central vein in the center is useful for the study of liver morphology, but doesn't give much information about the functional units of the liver. With the portal triad in the center of the functional lobule and blood flowing from this center in all directions toward various "central veins" some liver disease can be better explained. For example reduced arterial blood supply would manifest itself initially by affecting the cells nearest the central vein while toxic substances in the blood would show up first in cells near the portal triad. Liver macrophages, called Kupffer Cells, are present in sinusoids.