QuestionSBA
QuestionChoice
Incorrect - cranial nerve VII (the facial nerve) supplies the muscles of facial expression. It is not involved in eliciting the gag reflex, and so damage to this region would not cause deviation of the uvula.
10008391
b
Right Cranial Nerve VII
QuestionChoice
Correct - Cranial nerve X (the vagus nerve) has a range of functions in supplying sensory and motor innervation to the larynx, pharynx and abdominal viscera. In particular, it supplies the muscles of the soft palate responsible for swallowing and speech. Damage can cause characteristic deviation of the uvula. Deviation of the uvula away from the affected side (towards the left) and absence of contraction on the right are indicative of a right sided cranial nerve X lesion.
10008390
a
Right Cranial Nerve X
QuestionChoice
Incorrect - cranial nerve XII (the hypoglossal nerve) supplies the muscles of the tongue. It is not involved in eliciting the gag reflex. Damage to this region would not cause deviation of the uvula.
10008392
c
Right Cranial Nerve XII
QuestionChoice
Incorrect - cranial nerve XI (the accessory nerve) is responsible for innervating the sternocleidomastoid and trapezius muscles. It is not involved in the elicitation of the gag reflex. Damage to this region would not cause deviation of the uvula.
10008394
e
Right Cranial Nerve XI
QuestionChoice
Incorrect - cranial nerve IX (the glossopharyngeal nerve) is responsible for sensation when eliciting the gag reflex. As the patient still has sensation, cranial nerve IX is not affected. Furthermore, damage to this region would not cause deviation of the uvula.
10008393
d
Right Cranial Nerve IX
Concept
Chapter
2693
4666
Vomiting Reflex
Topic
149
Gastro-intestinal physiology
14225
A 57-year-old male is reviewed following a stroke. The clinician attempts to elicit a gag reflex using a tongue depressor. There is unilateral contraction of the soft palate on the left side, with a failure to rise on the right. Sensation on both sides of the oral cavity is intact. Deviation of the uvula to the left side is observed.

Which of the following cranial nerves is damaged?
a