part of part of has part has part adjacent to adjacent to somatostatin secreting cell PP cell type A enteroendocrine cell mucosa digestive tract gastrointestinal system mucosa BTO:0005568 MA:0001521 BTO:0000546 mucosa of gut SCTID:410433007 EMAPA:36591 digestive tract mucosa gut mucosa The gut mucosa of amphioxus has insulin-secreting cells. http://www.ncbi.nlm.nih.gov/pubmed/16417468 UBERON:0004786 A mucosa that is part of a gastrointestinal system. gut mucuous membrane alimentary part of gastrointestinal system lumen of digestive tract