Which cranial nerve is tested with eyes closed by touching different parts of the face?

The correct choice is the Trigeminal nerve, which is the fifth cranial nerve and is primarily responsible for sensation in the face as well as motor functions such as biting and chewing. When assessing sensory function, the Trigeminal nerve can be tested by using a light touch or a cotton swab on different areas of the face, including the forehead, cheeks, and jawline while the eyes are closed. This test evaluates the sensory pathways of the nerve, ensuring that the patient can perceive tactile stimuli properly.

In contrast, the other cranial nerves mentioned serve different functions. The Facial nerve is primarily involved in facial expressions, taste sensations from the anterior two-thirds of the tongue, and some aspects of salivary gland function. The Olfactory nerve is responsible for the sense of smell and is tested by having a patient identify different odors, not by tactile sensation. The Accessory nerve is associated with motor function, specifically controlling the sternocleidomastoid and trapezius muscles, and does not play a role in facial sensation. Therefore, the Trigeminal nerve is specifically the one tested through touch on the facial area while the eyes are closed.