Critical Care Registered Nurse (CCRN) Practice Exam

Which cranial nerve is primarily associated with tongue movement and strength testing?

1. CN VIII

2. CN VI

3. CN XII

4. CN X

The correct answer is: CN XII

The cranial nerve primarily associated with tongue movement and strength testing is the twelfth cranial nerve, also known as the hypoglossal nerve. This nerve is responsible for the motor control of most of the muscles of the tongue, which are essential for various functions such as speaking, swallowing, and manipulating food. When assessing tongue movement and strength, healthcare providers look for symmetry as the patient protrudes the tongue and for the ability of the tongue to move effectively from side to side. An impaired hypoglossal nerve can result in weakness or atrophy of the tongue muscles, impacting these essential functions and indicating potential neurological issues. The other cranial nerves listed play different roles. For example, the eighth cranial nerve is mainly responsible for hearing and balance, while the sixth cranial nerve controls lateral eye movement. The tenth cranial nerve, known as the vagus nerve, has multiple functions related to the heart, lungs, and digestive tract and does not primarily facilitate tongue movement.