accessory nucleus of optic tract medial accessory nucleus of optic tract medial terminal nucleus of the accessory optic tract The medial terminal nucleus is usually very prominent but it is reduced in primates (except, curiously, the tarsier), megachiropterans, Cynocephalus and Bradypus. Metatherians have a large medial terminal nucleus[Pettigrew et al. (1989)] UBERON:0013601 nucleus accessorius medialis tractus optici neuronames:1069 MBA:58 FMA:77653 BAMS:MT