Definitions

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Alternative form of chiasma.
  • n. Alternative form of chiasmus.

from the GNU version of the Collaborative International Dictionary of English

  • n. A commissure; an intersection or crossing of two tracts; especially, the optic commissure, or crucial union of the optic nerves.

from The Century Dictionary and Cyclopedia

  • n. In anatomy, a decussation or intersection; specifically, the decussation of the optic nerves which occurs in nearly all vertebrates. See second cut under brain.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. an intersection or crossing of two tracts in the form of the letter X

Etymologies

Latin; in sense 1, from chiasma, from Ancient Greek χίασμα (khiasma); in sense 2, from chiasmus, from Ancient Greek χιασμός (khiasmos "crossing, diagonal arrangement") (Wiktionary)

Examples

  • The optic chiasm is deeper in the brain than the corpus callosum, so it is not cut by the operation.

    Backing Into an Evidentiary Standard for ID

  • “This type of tumor presents a lot of secondary complications when it presses against the optic chiasm,” the doctor said, looking directly at Alex.

    The Opposite of Me

  • Drifting down the river in silence, the lovers indulge, by velar and glottal tension as well as ethical laxity, in a "grave untiring gaze" of reciprocated desire that seems released from the phonemic chiasm of "solitude" and

    Phonemanography: Romantic to Victorian

  • The discussion on chiasm (p. 49ff) is inadequate to understand the references.

    Female Purity (Niddah) Annotated Bibliography.

  • Women 3a apparently refers to Leviticus 12, while 3b apparently refers to Leviticus 15: 1 – 18, which seems an artificial breakdown because she excludes the niddah and zavah in 15: 19 – 30, putting them in a separate category to create the chiasm.

    Female Purity (Niddah) Annotated Bibliography.

  • The stimulus is a magnetic moment generated orthogonal to a circulating (chemo -) electrical current, or 'drift,' along the superior chiasm ( 'rift' between the brains) in the sagittal plane, so that the magnetic vector is 'positive'-going in the direction and axial from our right ear to our left ear -- where' positive 'is not denoting moral judgment, only a consistency of nomenclature by the righthand-thumb rule, for convenience.

    What Do Liberals Believe?

  • I'll give some further thought to the question of the chiasm, but even so it seems that whereas the transfiguration comes after it, within the structure (B') itself we have reference to the Son of Man coming with angels to render (final) judgment.

    Limits of Literalism

  • The slug created a downward bow-wave that caused edema and pressure on the optic chiasm.

    Duma Key

  • Also, half of the retinal fibers the nasal halves, closest to your nose cross over to the other hemisphere at the optic chiasm.

    Split Brain

  • Yeah, the optic chiasm is at the base of the brain, way below the corpus callosum, so if you were cutting the corpus and the optic you would have to go much deeper and cut through too many important subcorticals structures.

    Split Brain

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