Which of the following muscle is supplied by a direct branch from the trunk of mandibular division of trigeminal nerve?
**Core Concept**
The **mandibular division of the trigeminal nerve** is a mixed nerve that provides motor and sensory innervation. It supplies muscles of mastication and also has a role in sensory innervation of the face.
**Why the Correct Answer is Right**
The **medial pterygoid**, **lateral pterygoid**, **masseter**, and **temporalis** muscles are primarily supplied by the mandibular division of the trigeminal nerve. Among these, the **medial pterygoid** and others receive their nerve supply from its branches, but one specific muscle, the **lateral pterygoid**, is notable for receiving its innervation directly from the trunk of the mandibular division before it divides into its anterior and posterior branches.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because while the masseter is supplied by the mandibular division, its supply comes from the anterior (masseteric) branch, not directly from the trunk.
**Option C:** Incorrect as the temporalis muscle is supplied by the deep temporal nerves, which are branches of the anterior division of the mandibular nerve.
**Option D:** This option is not provided but would be incorrect based on similar reasoning related to the specific anatomy of nerve supply.
**Clinical Pearl / High-Yield Fact**
The **lateral pterygoid** muscle is unique due to its dual innervation for its two heads (upper and lower) but primarily receives its nerve supply directly from the mandibular division, making it clinically significant in neurologic examinations.
**Correct Answer:** D. Lateral pterygoid.