2nd pharyngeal arch is supplied by
**Core Concept**
The 2nd pharyngeal arch, also known as the hyoid arch, is a critical structure in the development of the head and neck. It is formed by the fusion of the first pair of pharyngeal arches and is supplied by a branch of the trigeminal nerve.
**Why the Correct Answer is Right**
The 2nd pharyngeal arch is primarily innervated by the mandibular division of the trigeminal nerve (CN V3). This nerve provides sensory and motor innervation to the muscles of mastication, including the medial pterygoid, lateral pterygoid, and tensor tympani. The mandibular nerve also supplies the auriculotemporal nerve, which provides sensory innervation to the tympanic membrane and the external auditory meatus.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the 2nd pharyngeal arch is not supplied by the glossopharyngeal nerve (CN IX), which primarily innervates the pharynx and the stylopharyngeus muscle.
**Option B:** This option is incorrect because the 2nd pharyngeal arch is not supplied by the vagus nerve (CN X), which primarily innervates the larynx and the pharynx.
**Option C:** This option is incorrect because the 2nd pharyngeal arch is not supplied by the facial nerve (CN VII), which primarily innervates the muscles of facial expression.
**Clinical Pearl / High-Yield Fact**
The 2nd pharyngeal arch is also known as the hyoid arch due to its association with the hyoid bone, which develops from the second and third pharyngeal arches.
**Correct Answer:** C.