Microscopy anatomy of the vertebral artery in the suboccipital and intracranial segments.

ABSTRACT

The authors studied the structure and the orientation of the connective-muscular component of the tunicae of the vertebral artery along the suboccipital and intracranial segments utilizing the following coloration methods: Weigert's resorcin fuchsin, Orcein solution and counterstain with Van Gieson's picrofuchsin. In the above mentioned segments, it was established that the wall of the vertebral artery exhibits a muscular structure. The tunica intima in both portions, has developed structure and the internal elastic lamina is evident; the tunica media is formed by fascicles of smooth muscle fibers disposed circularly in relation to the vascular lumen and interposed by thin elastic fibers. In the most external layer of the tunica media, these fibers form a external elastic lamina. The tunica adventitia is formed by a fibrous-elastic stratum which is reinforced by fascicles of circular collagenic fibers which mainly originates from the dura mater.