AskDefine | Define conjunctiva

Dictionary Definition

conjunctiva n : a transparent membrane covering the eyeball and under surface of the eyelid [also: conjunctivae (pl)]

User Contributed Dictionary

English

Noun

  1. A clear mucous membrane that lines the inner surface of the eyelid and the exposed surface of the eyeball or sclera.
membrane

Extensive Definition

The conjunctiva is a clear membrane that covers the sclera (white part of the eye) and lines the inside of the eyelids. It is made of lymphoid tissue.

Function

It helps lubricate the eye by producing mucus and tears, although a smaller volume of tears than the lacrimal gland. It also contributes to immune surveillance and helps to prevent the entrance of microbes into the eye.

Histology

The conjunctiva is typically divided into three parts:
  1. Palpebral or tarsal conjunctiva: The conjunctiva lining the eyelids.
  2. Fornix conjunctiva: The conjunctiva where the inner part of the eyelids and the eyeball meet, the palpebral conjunctiva is reflected at the superior fornix and the inferior fornix to become the bulbar conjunctiva. It is loose and flexible, allowing the free movement of the lids and eyeball. An ophthalmologist can insert eye drops into the lower eyelid space. The substance works its way up the surface of the eyeball and diffuse into the internal eye.
  3. Bulbar or ocular conjunctiva: The conjunctiva covering the eyeball, over the sclera. This region of the conjunctiva is bound tightly and moves with the eyeball movements.

Diseases and disorders

Disorders of the conjunctiva and cornea are a common source of eye complaints.
The surface of the eye is exposed to various external influences and is especially suspectible to trauma, infections, and allergic reactions.
The conjunctiva is best known because of its inflamed state, conjunctivitis (more commonly known as pinkeye).
Conjunctival irritation is one of the adverse health effects that can take place after overexposure to VOCs (Volatile organic compounds).

Additional images

References

External links

  • Medicinenet.com (1999). Conjunctiva. Retrieved July 25, 2004.
conjunctiva in Arabic: ملتحمة
conjunctiva in Bulgarian: Конюктива
conjunctiva in Bengali: কনজাংটিভা
conjunctiva in German: Bindehaut
conjunctiva in Spanish: Conjuntiva
conjunctiva in Esperanto: Konjunktivo
conjunctiva in Basque: Konjuntiba
conjunctiva in French: Conjonctive
conjunctiva in Italian: Congiuntiva
conjunctiva in Lithuanian: Junginė
conjunctiva in Dutch: Bindvlies
conjunctiva in Norwegian: Konjunktiva
conjunctiva in Polish: Spojówka
conjunctiva in Portuguese: Conjuntiva
conjunctiva in Finnish: Sidekalvo
conjunctiva in Chinese: 结膜
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