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Discussion Starter · #1 ·
You touch the left side of the pharynx and the patient's uvula deviates to the left and you touch the right side of the pharynx and the patient does not gag. Where is the lesion?

a- Left glossopharyngeal
b- Left vagus and glossopharyngeal
c- Right glossopharyngeal
d- Right vagus and glossopharyngeal
e- Right vugus
 

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Answer C

Right glossopharyngeal nerve lesion answer C
It serves the sensory part of the gag reflex, that's why the patient did not gag when we touched the right side
 

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Discussion Starter · #3 ·
Right glossopharyngeal nerve lesion answer C
It serves the sensory part of the gag reflex, that's why the patient did not gag when we touched the right side
Your answer is not correct
If it is only the right glossopharyngeal then why the uvula deviated when we touched the left side? think about it
 

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deviation of uvula to left means rt vagus nerve lesion but i want to ask if we touched rt side and no gag reflex why is glossopharyngeal it could be either glossophayngeal(afferent) or vagus(efferent)
 

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Because there was a gag on the left side

deviation of uvula to left means rt vagus nerve lesion but i want to ask if we touched rt side and no gag reflex why is glossopharyngeal it could be either glossophayngeal(afferent) or vagus(efferent)
Because when you touched the left side there was a gag (though a deviated one) which means that the left glossopharyngeal is working. But when you touched the right side there's was no gag at all (which means the afferent limb is cut).
Remember that afferent glossopharyngeal goes unilaterally to the brains stem and then it comes back "bilaterally" to both vagus nerves on both sides.
In this case it was the ability to elicit the gag on the left side that helped us to understand that the absent right sided gag is actually sensory not motor.
 
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