| Brain: Optic chiasm | ||
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| Visual pathway with optic chiasm (X shape outlined, red) (1543 image from Andreas Vesalius' Fabrica) | ||
| Latin | chiasma opticum | |
| Gray's | subject #197 883 | |
| MeSH | Optic+chiasm | |
The optic chiasm (Greek χίασμα, "crossing", from the Greek χλαζειν 'to mark with an X', after the Greek letter 'Χ', chi) is the part of the brain where the optic nerves partially cross. Andreas Vesalius ( Brussels, December 31, 1514 - Zakynthos, October 15, 1564) was an anatomist, Physician Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. This is a list of the subjects in Gray's Anatomy: IX Neurology Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Chi ( Uppercase Χ, Lowercase χ; Χι He is the 22nd letter of the Greek alphabet, pronounced as in English The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain.
Contents |
Pathways
Specifically, in the optic chiasm, the nerves connected to the right eye that attend to the right temporal visual field (located in the right retina) cross to the left half of the brain, while the nerves from the left eye that attend to the left temporal visual field (located in the left retina) cross to the right half of the brain.
This allows for parts of both eyes that attend to the right visual field to be processed in the left visual system in the brain, and vice versa. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain The visual system is the part of the Nervous system which allows organisms to see.
Optic chiasm in cats
In Siamese cats with certain genotypes of the albino gene, this wiring is disrupted, with less of the nerve-crossing than is normal, as a number of scholars have reported. The Siamese is one of the first distinctly recognised breeds of Oriental Cat. The genotype is the genetic constitution of a cell an organism or an individual (i Albinism (from Latin albus, "white" see extended etymology) is a form of hypopigmentary Congenital disorder, [1] To compensate for lack of crossing in their brains, they cross their eyes (strabismus). Strabismus (from Greek: στραβισμός strabismos, from στραβίζειν strabizein "to squint" from στραβός strabos [2]
This is also seen in albino tigers, as Guillery & Kaas report. The tiger ( Panthera tigris) is a member of the Felidae family the largest and the most powerful of the four " Big cats quot in the Genus [3]
Additional images
 Mesal aspect of a brain sectioned in the median sagittal plane. |
 Median sagittal section of brain. |
 Scheme showing central connections of the optic nerves and optic tracts. The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain. |
 Base of brain. |
 Coronal section of brain through anterior commissure. |
 The fornix and corpus callosum from below. The corpus callosum is a structure of the Mammalian Brain in the longitudinal fissure that connects the left and right Cerebral hemispheres It also facilitates |
 Diagram showing the positions of the three principal subarachnoid cisternæ. |
 The left optic nerve and the optic tracts. The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain. The optic tract is a part of the Visual system in the Brain. It is a continuation of the Optic nerve and runs from the Optic chiasm (where |
 The hypophysis cerebri in position. The pituitary gland, or hypophysis, is an Endocrine gland about the size of a Pea. Shown in sagittal section. A sagittal plane of the human body is an imaginary plane that travels from the top to the bottom of the body dividing it into left and right portions |
 Median sagittal through the hypophysis of an adult monkey. Semidiagrammatic. |
 3D schematic representation of optic tracts |
 Human brainstem anterior view |
See also
References
- ^ OMIA
- ^ R. Anatomy The Optic chiasm is formed by the union of the two optic nerves W. Guillery; J. H. Kaas. Genetic Abnormality of the Visual Pathways in a "White" Tiger. Science. 1973 Jun 22;180(92):1287-9. GS
- ^ Guillery, R. Visual pathways in albinos. Scientific American 1974 May;230(5):44-54. PubMed
- Jeffery, Glen. Architecture of the Optic Chiasm and the Mechanisms That Sculpt Its Development Physiol Rev, Oct 2001; 81: 1393 - 1414.
External links
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