part of start stage end stage descending trigeminal root TAO:0000192 zebrafish_anatomy ZFA:0000192 The bundle of the sensory root of the trigeminal nerve that descends in the medulla oblongata providing somatosensory input to the nucleus of the descending trigeminal root and to the medial funicular nucleus. radix descendens nervi trigemini medulla oblongata cranial nerve root unknown adult