part of part of superior colliculus layer of superior colliculus cytoarchitectural part of superior colliculus UBERON:0006783 NLXANAT:1005033 BAMS:SC-layers layer of optic tectum tectal layer The microstructure of the optic tectum / superior colliculus varies across species. As a general rule, there is always a clear distinction between superficial layers, which receive input primarily from the visual system and show primarily visual responses, and deeper layers, which receive many types of input and project to numerous motor-related brain areas. The distinction between these two zones is so clear and consistent that some anatomists have suggested that they should be considered separate brain structures. In mammals, neuroanatomists conventionally identify seven layers[WP]. Wikipedia:Superior_colliculus#Neural_circuit The tectum in lampreys has more layers than the tectum in hagfishes, likely related to the fact that vision is less well developed in hagfishes. tectal lamination is almost identical in reptiles and birds and is more restricted in mammals[http://icb.oxfordjournals.org/content/42/4/743.full] central nervous system cell part cluster nervous system cell part layer