Certified Post Anesthesia Nurse (CPAN) Practice Exam

In assessing cranial nerve function, which cranial nerve is tested by asking a child to smile and pucker their lips?

1. Cranial nerve V

2. Cranial nerve VII

3. Cranial nerve IX

4. Cranial nerve XII

The correct answer is: Cranial nerve VII

The cranial nerve that is tested by asking a child to smile and pucker their lips is the facial nerve, which is cranial nerve VII. This nerve is responsible for the muscles of facial expression, and by observing a child's ability to perform these actions, one can assess the integrity and function of the nerve. When the child smiles, the contraction of the muscles on both sides of the face is evaluated, and puckering the lips demonstrates controlled movement, which also involves this cranial nerve. In contrast, cranial nerve V, the trigeminal nerve, primarily deals with sensation in the face and motor functions such as chewing, not facial expressions. Cranial nerve IX, the glossopharyngeal nerve, is involved in taste and swallowing. Cranial nerve XII, the hypoglossal nerve, is responsible for tongue movements. Therefore, the actions of smiling and puckering specifically correlate with the function of cranial nerve VII.