Arteriole

This high powered electron micrograph shows the cell types found in the wall of an arteriole. Only part of the arteriole is shown. L = lumen of arteriole.

The arteriole is lined by an epithelium (E) forming the tunica intima of the arteriole. The tunica media is represented by a single layer of smooth muscle cells (M). The tunica adventitia is indistinct in an arteriole.

In this micrograph 2 small axons (arrows) can be seen in the connective tissue adjacent to the arteriole. It is possible that these are passing to supply the arteriolar muscle. Arterioles have a rich innervation. What branch of the nervous system would motor nerves innervating an arteriole in the lower limb be from?