part of develops into embryonic/larval visceral tracheal branch tracheal pit tracheal branch primordium visceral tracheal branch primordium P1 VisTra intestinal branch fly_anatomy.ontology visceral branch specific anlage embryonic visceral branch FBbt:00005587 FBbt:00017003 k branch Tracheal primordium that develops into the embryonic/larval visceral branch. It branches anteriorly from the dorsal portion of the transverse connective primordium during stage 12, coursing anteriorly and inwardly towards the gut. primary segmental tracheal branch primordium