Washington Esthetician State Board Practice Exam

Which cranial nerve is responsible for controlling chewing?

1. Seventh cranial nerve

2. Fifth cranial nerve

3. Third cranial nerve

4. Fourth cranial nerve

The correct answer is: Fifth cranial nerve

The fifth cranial nerve, also known as the trigeminal nerve, is primarily responsible for the sensation in the face and motor functions such as chewing. It has three branches: the ophthalmic, maxillary, and mandibular nerves. The mandibular branch specifically innervates the muscles involved in mastication, making it essential for the chewing process. This nerve allows the transmission of signals to and from the jaw muscles, enabling coordinated movement that is crucial for effective chewing. The other cranial nerves listed do not play a significant role in the chewing process. The seventh cranial nerve, known as the facial nerve, primarily controls the muscles of facial expression and does not innervate the chewing muscles. The third cranial nerve, or oculomotor nerve, is mainly involved in eye movement and does not have a role in mastication. Similarly, the fourth cranial nerve, the trochlear nerve, is primarily responsible for the movement of a single muscle that controls downward eye movement and does not contribute to chewing actions. Thus, the fifth cranial nerve is correctly identified as the nerve that controls chewing due to its direct role in motor function of the jaw muscles.