This is a photograph of a human liver sample viewed under low power (10x). It was taken with a Samsung SH100 digital camera through the eyepiece of a compound microscope. This image clearly shows a central vein (with red blood cells in the lumen). The central vein is surrounded by unstained vessels called sinusoids. The sinusoids feed into the central vein. Between the sinusoids, hepatocytes, the parenchymal cell of the liver, are visible. The hepatocytes are distinctly shaped with a centrally located basophilic nucleus. Surrounding the central vein is simple squamous epithelium (characteristic of blood vessels). What is not characteristic of a blood vessel is the lack of surrounding smooth muscle and connective tissue. Rather this vein is directly surrounded by the hepatocytes of the parenchyma.