Which cranial nerve is tested when a person is asked to stick out their tongue?

The cranial nerve that is tested when a person is asked to stick out their tongue is the Hypoglossal nerve, which is cranial nerve twelve. This nerve is primarily responsible for the motor control of the muscles of the tongue, allowing for movements necessary for speech, swallowing, and manipulating food. When the patient sticks out their tongue, the healthcare provider can assess the movement and strength of the tongue muscles, checking for any signs of weakness, atrophy, or deviation, which are important in diagnosing neurological conditions.

In contrast, the other nerves listed have different functions. The Optic nerve is associated with vision, the Trigeminal nerve handles sensations in the face and motor functions such as chewing, and the Facial nerve controls the muscles of facial expression. None of these directly relate to the muscular control involved in tongue movement. Therefore, the selection of the Hypoglossal nerve is accurate as it directly relates to the action of sticking out the tongue.