Arteriole and vein -
plastic section (100x objective lens)
This plastic section from the esophagus shows an arteriole
(upper right) and a vein (center) cut in cross
section.
The arteriole is lined by a layer of endothelial cells around which is wrapped
a single layer of smooth muscle. Two endothelial
cell nuclei can be seen cut in cross section, whereas a single smooth
muscle cell nucleus is cut longitudinally.
The vein is filled with erythrocytes and lined
by a simple squamous epithelium of endothelial
cells, whose nuclei are either flattened
at the boundary of the lumen or bulge into it. The nuclei that can be seen
outside of the endothelium belong to smooth muscle cells (larger, more oval
in shape) and fibroblasts (flattened, more elongated).
