Editing Midbrain (section)

===Tectum===
{{Further|Superior colliculus|Inferior colliculus}}
[[File:Gray719.png|thumb|left|Principal connections of the tectum]]
The tectum (Latin for ''roof'') is the part of the midbrain dorsal to the [[cerebral aqueduct]].<ref name="Sinnatamby-2011" />The position of the tectum is contrasted with the [[tegmentum]], which refers to the region in front of the [[ventricular system]], or floor of the midbrain.

It is involved in certain [[reflex]]es in response to visual or auditory stimuli. The [[reticulospinal tract]], which exerts some control over alertness, takes input from the tectum,<ref>{{Cite book|title=Principles of Neural Science|last=Kandel|first=Eric|publisher=McGraw-Hill|year=2000|isbn=0-8385-7701-6|pages=[https://archive.org/details/isbn_9780838577011/page/669 669]|url-access=registration|url=https://archive.org/details/isbn_9780838577011/page/669}}</ref> and travels both rostrally and caudally from it.

The [[corpora quadrigemina]] are four mounds, called colliculi, in two pairs – a superior and an inferior pair, on the surface of the tectum. The [[superior colliculus|superior colliculi]] process some visual information, aid the [[decussate|decussation]] of several fibres of the [[optic nerve]] (some fibres remain ipsilateral), and are involved with [[Saccade|saccadic eye movements]]. The [[tectospinal tract]] connects the superior colliculi to the [[cervical nerve]]s of the [[neck]], and co-ordinates head and eye movements. Each superior colliculus also sends information to the corresponding [[lateral geniculate nucleus]], with which it is directly connected. The [[homology (biology)|homologous]] structure to the superior colliculus in non mammalian vertebrates including [[fish]] and [[amphibian]]s, is called the [[Superior colliculus#Optic tectum|optic tectum]]; in those animals, the optic tectum integrates sensory information from the eyes and certain auditory reflexes.<ref>Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005</ref><ref>{{cite journal|title= Functions of the optic lobes or corpora quadrigemina|pages=149–173|author=Ferrier, David|author-link=David Ferrier|year=1886|url=http://psycnet.apa.org/books/12789/005|doi=10.1037/12789-005|url-access=subscription}}</ref>

The [[inferior colliculus|inferior colliculi]] – located just above the [[trochlear nerve]] – process certain auditory information. Each inferior colliculus sends information to the corresponding [[medial geniculate nucleus]], with which it is directly connected.