When a patient says Ah the right uvula presses the palate which of the following nerve is damaged ?
Ans. is 'c' i.e., Left X CN Assessment of the movement of soft palate - Both IX and X CNs are tested: The glossopharyngeal nerve (IX CN) is a mixed nerve with motor, sensory and some parasympathetic activity. It carries sensory input from the palate and pharynx and the taste from the posterior third of the tongue. It provides afferent limb of the gag reflex. The vagus (X CN) is also a mixed nerve with motor, sensory and parasympathetic activity. It provides the motor supply to the pharynx, soft palate and larynx and provides the efferent limb to the gag reflex. Normally on oral examination thesoft palate is symmetrical with the uvula dangling in the centre and dividing the soft palate. When the patient is asked to say AAAh! The soft palate should elevate symmetrically and the uvula should remain centric. If there is unilateral weakness of the soft palate the uvula is pulled away from the weakened side. Now in the question given when the patient says aaah the right uvula presses the palate i. e. the right side soft palate pulls the uvula away from the weak left side. The weakness of the left soft palate can be because of the weakness of the left IX or X cranial nerves.
Rght X CN
Right XII CN
Left X CN
Right XII CN