Question

which cranial nerve innervates the temporalis muscle?
trigeminal (cn 5)
facial (cn 7)
glossopharyngeal (cn 9)
hypoglossal (cn 12)

Explanation:

The trigeminal nerve (CN 5) has a motor component that innervates muscles of mastication, including the temporalis muscle. The facial nerve (CN 7) is mainly for facial expression muscles. The glossopharyngeal nerve (CN 9) is involved in functions like taste and swallowing in part of the pharynx. The hypoglossal nerve (CN 12) innervates tongue muscles.

Answer:

Trigeminal (CN 5)