optic chiasm
Học thuậtThân thiện
Definition
Noun: 1. The crossing point of the optic nerves: The optic chiasm is a specific structure at the base of the brain where the optic nerves from the left and right eyes partially cross. This crossing allows visual information from each eye to be processed by both hemispheres of the brain.
Usage
- The term "optic chiasm" is used exclusively in anatomical, medical, and biological contexts to describe this specific neural structure.
- It is typically preceded by the definite article "the" (e.g., optic chiasm).
- It functions as a singular noun.
Examples
- Noun:
- Damage to the optic chiasm can cause a specific type of vision loss.
- The surgeon carefully avoided the optic chiasm during the procedure.
- In humans, approximately half of the nerve fibers cross at the optic chiasm.
Advanced Usage
- "Lesion at the optic chiasm": A medical term for damage or abnormality located at this specific crossing point, often leading to bitemporal hemianopia (loss of the outer visual fields).
- "Compression of the optic chiasm": A condition where a tumor or other growth puts pressure on this structure, disrupting visual signals.
Variants and Related Words
- Optic chiasma (noun): A less common variant spelling with the same meaning. "Chiasma" comes directly from the Greek word for "crossing."
- Chiasmatic (adjective): Relating to the optic chiasm (e.g., region).
- Optic nerve (noun): The nerve bundle that carries visual information from the eye to the optic chiasm.
- Optic tract (noun): The nerve pathway that continues from the optic chiasm to the brain's visual centers.
Synonyms
- Chiasm: In neurological contexts, "chiasm" can be used as a shorthand for the optic chiasm, though it can refer to other crossing structures in the body.
- Optic decussation: A more technical synonym emphasizing the crossing ("decussation") of the neural pathways.
Related Terms (Not Phrasal Verbs or Idioms)
Given its highly technical nature, "optic chiasm" is not used in phrasal verbs or idioms. It is a precise anatomical term.
Noun
- the crossing of the optic nerves from the two eyes at the base of the brain