optic chiasma การใช้

• The specific area of the visual pathway at which compression by these tumours occurs is at the optic chiasma.
• Fabrica, published in 1543, showing the base of the human brain, including optic chiasma, cerebellum, olfactory bulbs, etc.
• After the optic chiasma the visual tracts are referred to as the optic tracts, which enter the thalamus to synapse at the lateral geniculate nucleus ( LGN ).
• The axons from the nasal half cross the brain at the optic chiasma to join with axons from the temporal half of the other eye before passing into the lateral geniculate body.
• Visual information is then sent to the brain from retinal ganglion cells via the optic nerve to the optic chiasma : a point where the two optic nerves meet and information from the temporal ( contralateral ) visual field crosses to the other side of the brain.
• This surface is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the prechiasmatic 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 into the orbital cavity.
• Occupying the posterior part of the commissure of the optic chiasma is a strand of fibers, the "'Ventral supraoptic decussation "'( "'commissure of Gudden "', "'Gudden's inferior commissure "'), which is not derived from the optic nerves; it forms a connecting link between the medial geniculate bodies.
• 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 sympathetic nerve fibres ) into the orbital cavity.
• Seen in an MRI as two individual arteries at this hairpin, a carotid artery dolichoectasia can progress so far as to produce a second hairpin turn and appear as three individual arteries on an MRI . In the case of a dolichoectasia of the Internal Carotid Artery ( ICD ), the pathogenesis is primarily related to compression of the Optic Nerves at the Optic Chiasma ( see Fig . 1 and 2 ).