part_of part of part of longitudinal muscle cell PMID:26904543 longitudinal muscle PMID:30471994 longitudinal muscle cell ISBN:9780070316607 longitudinal fiber https://github.com/obophenotype/planaria-ontology/blob/master/metadata/planarefs/planaref-0000005.md PMID:27551436 https://orcid.org/0000-0003-2569-1939 | https://orcid.org/0000-0002-7535-4660 PMID:28461239 Planarian_Anatomy Body wall muscle fibers arrayed along the anteroposterior axis. Upon regeneration, these muscles are thought to be established from truncated pre-existing fibers.Inner most body wall muscle fibers arrayed along the anteroposterior axis. These fibers are thicker than the outer longitudinal muscle fibers. The pattern of these muscles differs along the dorsoventral axis, with the dorsal arrangement converging at the central zone of the anterior pole. The ventral arrangement is more parallel or may diverge slightly as it approaches the ventral pole. PMID:28807897 longitudinal muscle fiber PMID:23903188 body wall longitudinal fiber BW longitudinal fiber muscle cell body wall musculature