Term Name:	periplasmic flagellum
Synonyms:
Definition:	Flagellar filaments located in the periplasmic space; characterized in spirochetes, in which they are essential for shape and motility. Composed of a core surrounded by two sheath layers, the flagella rotate to allow migration of the cell through viscous media, which would not be possible using external flagella.
Ontology:	GO: Cellular Component [GO:0055040]    QuickGO    AmiGO