vagina vagina muscular layer of vagina http://purl.obolibrary.org/obo/UBERON_0006652 http://purl.org/sig/ont/fma/fma19976 A09.1.04.010 The layer of smooth muscle with bundles of circular fibers internal to longitudinal fibers (those that run lengthwise) that is between the mucosa and the adventitia in the vagina. muscular coat of vagina muscular layer muscular layers of vagina muscular coat smooth muscle layer