part of abdominal segment 1 larval abdominal segment 1 larval abdominal median nerve larval abdominal 1 median nerve fly_anatomy.ontology VFB:FBbt_00002598 Median nerve that exits the dorsal part of abdominal neuromere 1 (Santos et al., 2006). It has a large swelling, corresponding to an abdominal neurohemal organ. It does not give rise to transverse nerves in the first instar (Gorczyca et al., 1994), but does branch relatively proximally to produce these nerves in the third instar (Santos et al., 2006). FBbt:00002598 MeN-1