Examine the anastomosing plates of hepatocytes between the portal tracts and the central venule (Figs. 16-11 through 16-14).

• Identify the vascular sinusoids between the plates of hepatocytes, the endothelial cells lining the sinusoids, and
• Scattered dark, rounded macrophages (Kupffer cells) (Fig. 16-14) in the sinusoidal lining.

Why might the hepatocytes near the portal tract appear different from those near the central vein?

On slide 24 notice the different staining properties of hepatocytes in regions of a lobule at various distances from the portal tract.

• These differences reflect different metabolic components and other changes in hepatocytes exposed to blood with different changing levels of oxygen and metabolites.

Examine carefully the ultrastructure of hepatocytes and sinusoids (Fig. 16-15).

• Identify microvilli projecting from the hepatocytes into a space beneath the discontinuous endothelial lining of the sinusoid,
• The perisinusoidal space (of Disse).
• Identify also the channels present between adjacent hepatocytes,
• The bile canaliculi, into which bile is secreted, to be drained initially via the bile duct branch in the portal tract. Bile is both an exocrine and an excretory product.

What are some substances added to and removed from blood as it goes through the liver, entering via the hepatic portal vein, passing through lobules, to its exit via the hepatic vein?

What is the fate of the excreted substances removed from blood in the liver?

Now for the gallbladder.