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nictitating membrane
nic·ti·tat·ing membrane N0098800 (nĭk′tĭ-tā′tĭng)n. A transparent inner eyelid in many vertebrates that closes to protect and moisten the eye. Also called third eyelid.nictitating membrane (ˈnɪktɪˌteɪtɪŋ) n (Zoology) (in reptiles, birds, and some mammals) a thin fold of skin beneath the eyelid that can be drawn across the eye. Also called: third eyelid or haw nic′titating mem′brane
n. a thin membrane, present in many animals, that can be drawn across the eyeball for protection. [1705–15] nic·ti·tat·ing membrane (nĭk′tĭ-tā′tĭng) A transparent inner eyelid in birds, reptiles, amphibians, and some mammals that protects and moistens the eye without blocking vision.Thesaurus| Noun | 1. |  nictitating membrane - a protective fold of skin in the eyes of reptiles and birds and some mammalsthird eyelideye, oculus, optic - the organ of sightprotective fold - a flap of tissue that protects what it covershaw - the nictitating membrane of a horse |
nictitating membrane
pli·ca sem·i·lu·na·'ris of con·junc·ti·'va [TA] 1. the semilunar fold formed by the palpebral conjunctiva at the medial angle of the eye; 2. a fold of the conjunctival mucous membrane found in many animals; normally partially hidden in the medial canthus of the eye when at rest, it may be extended to cover part or all of the cornea in a winklike action to clean the cornea, as in birds. Synonym(s): membrana nictitans, nictitating membrane, palpebra III, palpebra tertia, third eyelid Synonym(s): plica semilunaris conjunctivae [TA], plica lunata, plica semilunaris of eye, semilunar conjunctival foldnictitating membrane (nĭk′tĭ-tā′tĭng)n. A transparent inner eyelid in many vertebrates that closes to protect and moisten the eye. Also called third eyelid.nictitating membrane the third eyelid that occurs in birds, reptiles, and some mammals, sharks and amphibians. It is transparent and flicks over the eyeball from the inner (anterior) corner of the eye to clean and moisten the eyeball without shutting out the light. In some diving birds such as auks, there is a lens-like window in the membrane which adjusts the focus of the eye under water.nictitating membrane
Synonyms for nictitating membranenoun a protective fold of skin in the eyes of reptiles and birds and some mammalsSynonymsRelated Words- eye
- oculus
- optic
- protective fold
- haw
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