Search results
Results From The WOW.Com Content Network
In neuroanatomy, the optic chiasm, or optic chiasma (/ ɒ p t ɪ k k aɪ æ z əm /; from Greek χίασμα 'crossing', from Ancient Greek χιάζω 'to mark with an X'), is the part of the brain where the optic nerves cross. It is located at the bottom of the brain immediately inferior to the hypothalamus. [1]
The optic tract is a continuation of the optic nerve that relays information from the optic chiasm to the ipsilateral lateral geniculate nucleus (LGN), pretectal nuclei, and superior colliculus. [14] The optic tract represents the first stage in the visual pathway in which visual information is transferred in a homonymous nature. [15]
Chiasms are found in vertebrates but also in invertebrates. The optic chiasm in vertebrates can be of type I or II. [1] [4] However, an optic chiasm of type III is found in many insects [2] and in cephalopods. [3] In vertebrates, three of the cranial nerves show a chiasm. The optic chiasm of the optic tract (type I or II)
The optic nerves from both eyes meet and cross at the optic chiasm, [33] [34] ... Proper function of the visual system is required for sensing, processing, and ...
The opening of each optic canal is placed at either lateral end of the chiasmatic sulcus. The optic chiasm is situated superior and quite posterior to the chiasmatic groove (and not against the groove as the name suggests). [2]: 509 Chiasmatic groove
In humans, the optic nerve is derived from optic stalks during the seventh week of development and is composed of retinal ganglion cell axons and glial cells; it extends from the optic disc to the optic chiasma and continues as the optic tract to the lateral geniculate nucleus, pretectal nuclei, and superior colliculus. [1] [2]
Bitemporal hemianopsia is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field. It is usually associated with lesions of the optic chiasm, the area where the optic nerves from the right and left eyes cross near the pituitary gland.
The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove), above and behind which lies the optic chiasma; the groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery (with accompanying ...