title: Morphological modulations in helical muscles (Aschelminthes and Annelida).
mesh_terms: D000818:Animals; D000845:Annelida / Q000033:anatomy & histology* / Q000502:physiology; D006376:Helminths / Q000033:anatomy & histology* / Q000502:physiology; D008953:Models, Anatomic; D009119:Muscle Contraction; D009132:Muscles / Q000033:anatomy & histology* / Q000502:physiology / Q000648:ultrastructure; D009210:Myofibrils / Q000648:ultrastructure; D010802:Phylogeny