part_of part of part of contained in existence overlaps existence starts during or after material entity Stage 6 Stage 7 Stage 8 digestive system mouth anus PMID:21458439 PMID:26457503 PMID:17905225 PMID:27122174 PMID:30485821 PMID:19174194 PMID:23954785 PMID:30471994 PMID:21806978 PMID:21295481 ISBN:9780070316607 https://orcid.org/0000-0003-2569-1939 | https://orcid.org/0000-0002-7535-4407 PMID:27074666 The sole point of entry and exit for the Triclad planarian flatworm gut. The mouth is connected to the pharyngeal pouch to allow for exit and re-entry of the pharynx on the ventral side of the animal. The mouth contains several cell types, including epithelial cells, muscle, and secretory cells. PMID:20707997 OCLC:16809160 Planarian_Anatomy PMID:30399335 PMID:27063937 PMID:28807897 PMID:19211673 PMID:18287199 manus PMID:26556349 PMID:17251262 PMID:27034770 UBERON:0000165 PMID:29674431 posterior region of the whole animal ventral region of the whole animal juvenile stage parapharyngeal region organ adult hermaphrodite asexual adult