Optic chiasm - wikipedia Optic chiasm For other meanings of `` chiasm '', see Chiasm. Optic chiasma Brain viewed from below ; the front of the brain is above. Visual pathway with optic chiasm ( X shape ) is shown in red ( 1543 image from Andreas Vesalius ' Fabrica ) Optic nerves, chiasm, and optic tracts Details Part of Visual system Identifiers Latin chiasma opticum MeSH A08. 800.800. 120.680. 600 NeuroLex ID Optic chiasm TA A14. 1.08. 403 FMA 62045 Anatomical terms of neuroanatomy ( edit on Wikidata ) The optic chiasm or optic chiasma ( / ɒptɪk kaɪæzəm / ; Greek χίασμα, `` crossing '', from the Greek χιάζω ' to mark with an X ', after the Greek letter ' Χ ', chi ) is the part of the brain where the optic nerves partially cross. The optic chiasm is located at the bottom of the brain immediately below the hypothalamus. The optic chiasm is found in all vertebrates, although in cyclostomes ( lampreys and hagfishes ) it is located within the brain. Contents 1 Structure 2 Other animals 3 Additional images 4 History 5 See also 6 References 7 External links Structure The optic nerve fibres on the nasal sides of each retina cross over ( decussate ) to the opposite side of the brain via the optic nerve at the optic chiasm ( decussation of medial fibers ). The temporal hemiretina, on the other hand, stays on the same side. The inferonasal retina are related to anterior portion of the optic chiasm whereas superonasal retinal fibers are related to the posterior portion of the optic chiasm. The crossing over of optic nerve fibres at the optic chiasm allows the visual cortex to receive the same hemispheric visual field from both eyes. Superimposing and processing these monocular visual signals allow the visual cortex to generate binocular and stereoscopic vision. For example, the right visual cortex receives the temporal visual field from the left eye, and the nasal visual field from the right eye, which results in the right visual cortex producing a binocular image of the left hemispheric visual field. The net result of optic nerve crossing over at the optic chiasm is for the right cerebral hemisphere to sense and process left hemispheric vision, and for the left cerebral hemisphere to sense and process right hemispheric vision. This crossing is an adaptive feature of frontally oriented eyes, found mostly in predatory animals requiring precise visual depth perception. ( Prey animals, with laterally positioned eyes, have little binocular vision, so there is a more complete crossover of visual signals. ) Beyond the optic chiasm, with crossed and uncrossed fibers, the optic nerves become optic tracts. The signals are passed on to the lateral geniculate body, in turn giving them to the occipital cortex ( the outer matter of the rear brain ). Other animals In Siamese cats with certain genotypes of the albino gene, this wiring is disrupted, with more of the nerve - crossing than is normal, as a number of scholars have reported. To compensate for lack of crossing in their brains, they cross their eyes ( strabismus ). This is also seen in albino tigers, as Guillery & Kaas report. Additional images Scheme showing central connections of the optic nerves and optic tracts. Base of brain. 3D schematic representation of optic tracts Transformations of the visual field toward the visual map on the primary visual cortex. Human brainstem anterior view Optic chiasm Optic chiasma Cerebrum. Inferior view. Deep dissection. Cerebrum. Inferior view. Deep dissection. History The crossing of nerve fibres, and the impact on vision that this had, was probably first identified by Persian physician `` Esmail Jorjani '', who appears to be Zayn al - Din Gorgani ( 1042 -- 1137 ). See also Wikimedia Commons has media related to Optic chiasm. Chiasmal syndrome References Jump up ^ Colman, Andrew M. ( 2006 ). Oxford Dictionary of Psychology ( 2nd ed. ). Oxford University Press. p. 530. ISBN 0 - 19 - 861035 - 1. Jump up ^ Bainbridge, David ( 30 June 2009 ). Beyond the Zonules of Zinn : A Fantastic Journey Through Your Brain. Harvard University Press. p. 162. ISBN 978 - 0 - 674 - 02042 - 9. Retrieved 22 November 2015. Jump up ^ de Lussanet, Marc H.E. ; Osse, Jan W.M. ( 2012 ). `` An ancestral axial twist explains the contralateral forebrain and the optic chiasm in vertebrates ''. Animal Biology. 62 ( 2 ) : 193 -- 216. arXiv : 1003.1872. doi : 10.1163 / 157075611X617102. ISSN 1570 - 7555. Jump up ^ Purves, Dale ; Augustine, George ; Fitzpatrick, David ; Hall, William ; LaMantia, Anthony - Samuel ; White, Leonard ( 2012 ). Neuroscience. Sinauer Associates. p. 261. ISBN 978 - 0 - 87893 - 695 - 3. Jump up ^ `` eye, human. '' Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2009 Jump up ^ Schmolesky MT, Wang Y, Creel DJ, Leventhal AG. `` Abnormal retinotopic organization of the dorsal lateral geniculate nucleus of the tyrosinase - negative albino cat ''. J Comp Neurol. 427 ( 2 ) : 209 -- 19. doi : 10.1002 / 1096 - 9861 ( 20001113 ) 427 : 2 < 209 : : aid - cne4 > 3.0.co ; 2 - 3. PMID 11054689. Jump up ^ Guillery, RW ; Kaas, JH ( June 1973 ). `` Genetic abnormality of the visual pathways in a `` white '' tiger ``. Science. 180 ( 4092 ) : 1287 -- 9. Bibcode : 1973Sci... 180.1287 G. doi : 10.1126 / science. 180.4092. 1287. PMID 4707916. Jump up ^ Guillery RW ( May 1974 ). `` Visual pathways in albinos ''. Sci. Am. 230 ( 5 ) : 44 -- 54. doi : 10.1038 / scientificamerican0574 - 44. PMID 4822986. Jump up ^ Davis, Matthew C. ; Griessenauer, Christoph J. ; Bosmia, Anand N. ; Tubbs, R. Shane ; Shoja, Mohammadali M. ( 2014 - 01 - 01 ). `` The naming of the cranial nerves : A historical review ''. Clinical Anatomy. 27 ( 1 ) : 14 -- 19. doi : 10.1002 / ca. 22345. ISSN 1098 - 2353. Jeffery G ( October 2001 ). `` Architecture of the optic chiasm and the mechanisms that sculpt its development ''. Physiol. Rev. 81 ( 4 ) : 1393 -- 414. PMID 11581492. External links `` Anatomy diagram : 13048.000 - 1 ''. Roche Lexicon - illustrated navigator. Elsevier. Archived from the original on 2014 - 01 - 01. The cranial nerves terminal Nuclei Septal nuclei Course no significant branches olfactory Nuclei Anterior olfactory nucleus Course olfactory bulb olfactory tract optic Nuclei Lateral geniculate nucleus Course optic chiasm optic tract oculomotor Nuclei Oculomotor nucleus Edinger -- Westphal nucleus Branches superior parasympathetic root of ciliary ganglion / ciliary ganglion inferior trochlear Nucleus Branches no significant branches trigeminal Nuclei PSN Spinal trigeminal nucleus MN TMN Course trigeminal ganglion Branches ophthalmic maxillary mandibular abducens Nucleus Branches no significant branches facial near origin intermediate nerve geniculate inside facial canal greater petrosal pterygopalatine ganglion nerve to the stapedius chorda tympani lingual nerve submandibular ganglion at stylomastoid foramen posterior auricular suprahyoid digastric stylohyoid parotid plexus temporal zygomatic buccal mandibular cervical Nuclei Facial motor nucleus Solitary nucleus Superior salivary nucleus vestibulocochlear Nuclei Vestibular nuclei Cochlear nuclei cochlear nerve striae medullares lateral lemniscus vestibular Scarpa 's ganglion glossopharyngeal before jugular fossa ganglia superior inferior after jugular fossa tympanic tympanic plexus lesser petrosal otic ganglion stylopharyngeal branch pharyngeal branches tonsillar branches lingual branches carotid sinus Nuclei Nucleus ambiguus Inferior salivatory nucleus Solitary nucleus vagus before jugular fossa ganglia superior inferior after jugular fossa meningeal branch auricular branch neck pharyngeal branch pharyngeal plexus superior laryngeal external internal recurrent laryngeal ( inferior ) superior cervical cardiac thorax inferior cardiac pulmonary vagal trunks anterior posterior abdomen celiac renal hepatic anterior gastric posterior gastric Nuclei Nucleus ambiguus Dorsal nucleus of vagus nerve Solitary nucleus accessory Nuclei Nucleus ambiguus Spinal accessory nucleus cranial spinal hypoglossal Nucleus Branches lingual Retrieved from `` https://en.wikipedia.org/w/index.php?title=Optic_chiasm&oldid=815119276 '' Categories : Cerebrum Visual system Optic nerve Hidden categories : Medicine infobox template using GraySubject or GrayPage Articles containing Ancient Greek - language text All articles with unsourced statements Articles with unsourced statements from January 2016 Talk Contents About Wikipedia Čeština Deutsch Eesti Español فارسی Français Italiano עברית Nederlands Polski Português Русский Simple English Српски / srpski Svenska தமிழ் 中文 Edit links This page was last edited on 12 December 2017, at 21 : 54. 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Question: where does the optic nerve cross the midline ​
Answer: optic chiasm; The optic chiasm or optic chiasma