title: The nervous system and the segmentation of the head in the Annulata.
mesh_terms: D002492:Central Nervous System Depressants; D006257:Head; D006652:Histological Techniques; D009420:Nervous System / Q000033:anatomy & histology*
chemical_list: D002492:Central Nervous System Depressants
keywords: NERVOUS SYSTEM/anatomy and histology