part of develops from embryonic stomatogastric nervous system rostral vesicle of iSNSP intermediate vesicle of iSNSP tip stomatogastric nervous system precursor delaminating stomatogastric nervous system precursor embryonic frontal ganglion parapharyngeal ganglion VFB:FBbt_00005668 FBbt:00005668 fly_anatomy.ontology A small paired ganglion of the embryonic stomatogastric nervous system attached to the anterior surface of the brain. It consists of approximately 25-30 neurons that form a U-shaped ganglion wedged between the anterior aspect of the brain hemispheres and the dorsal pharynx. The somata of the neurons surround a sparse neuropil domain and are enclosed in a glial sheath. Lateral projections from these neurons form the frontal connective. Medial projections that turn anteriorly on reaching the midline form the frontal nerve. Medial projections that turn posteriorly on reaching the midline form the recurrent nerve. The term parapharyngeal ganglion was previously used to designate the embryonic frontal ganglion (Campos-Ortega and Hartenstein, 1997). frontal ganglion frontal ganglion primordium anterior ectoderm derivative