This high magnification
image of a section through an arteriole is focused
on the nuclei of the endothelial cells (En) of
the lining tunica intima. Note that the nuclei of the endothelial cells are
oriented with their long axes parallel to the long axis of the blood vessel.
Several smooth muscle nuclei, which are oriented with their long axes perpendicular
to the long axis of the vessel, can seen. Some are cut in cross section (SM-xs)
and others (mostly out of focus) are seen cut in longitudinal section
(SM-ls). Adjacent to the arteriole is a vein
(V).
