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  1. #1
    sukhjod is offline Newbie 510 points
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    Please help for one Q in Tommy's HY

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    Say your pt comes in and you touch both her corneas one at a time with a q-tip, and you note that ONLY the LEFT eye blinks, then which cranial nerve is activated?
    Answer:
    Right CN7 (NOT THE LEFT ONE, common mistake). I do not understand, Why?
    Could someone help me, please!

  2. #2
    atropine is offline Member 512 points
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    Afferent input is fine (perceiving the noxious stimulus), only efferent output (blinking) is affected in the right eye.

  3. #3
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    dxk7874 is offline Junior Member 510 points
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    Corneal Reflex Touch
    Afferent limb: CN 5 trigeminal (receives input)
    Efferent limb: CN 7 facial (sends signal out bilateral blink)

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