choroid
/'kourɔid/
Học thuậtThân thiện
Definition
- Noun:
- A highly vascular membrane in the eye: The choroid is a layer of tissue in the eye, located between the retina and the sclera. It is rich in blood vessels that supply nutrients and oxygen to the outer layers of the retina.
- A dark pigmented layer: The choroid contains a dark pigment (melanin) that absorbs excess light, minimizing internal light scattering and preventing reflections that would blur vision.
Usage Examples
- Noun:
- The ophthalmologist explained that the choroid nourishes the retinal cells.
- Inflammation of the choroid, known as choroiditis, can affect vision.
- The dark pigment in the choroid acts like the black paint inside a camera, reducing glare.
Advanced Usage
- "Choroidal" (adjective): Pertaining to the choroid.
- Choroidal thickness can be measured with specialized eye scans.
- "Choroid plexus" (noun): A related but distinct structure in the brain that produces cerebrospinal fluid. This is a compound term listed here as a related concept, not as a definition of "choroid" itself.
Variants and Related Words
- Choroidal (adj): Of or relating to the choroid.
- Chorioid (n): An alternate, less common spelling for "choroid."
- Uvea (n): The vascular layer of the eye, which includes the choroid, ciliary body, and iris. The choroid is part of the uvea.
Synonyms
- Choroid coat: A synonymous term, emphasizing its layer-like structure.
- Vascular tunic: A more general anatomical term for a vascular layer, which can refer to the choroid in the context of the eye.
Related Medical Terms (Not Phrasal Verbs or Idioms)
- Choroiditis (n): Inflammation of the choroid.
- Choroidopathy (n): Any disease of the choroid.
- Choroidal neovascularization (n): An abnormal growth of blood vessels from the choroid into the retina.
Noun
- a highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye