About lateral pterygoid muscle which of the following statement is true -a) Protude mandibleb) Arise from infra temporal fossa & lateral pterygoid platec) Bipolar headd) Supplied by facial nervee) Inserted into fovea of mandible
**Core Concept**
The lateral pterygoid muscle is a crucial muscle of mastication, responsible for the protrusion and depression of the mandible. It plays a vital role in the movement of the jaw, particularly during the opening and closing of the mouth.
**Why the Correct Answer is Right**
The lateral pterygoid muscle arises from two heads: the superior head, which originates from the infratemporal surface of the greater wing of the sphenoid bone, and the inferior head, which originates from the lateral surface of the lateral pterygoid plate. Both heads converge to form a single tendon that inserts into the neck of the mandible, specifically into the fovea of the mandible. This muscle is supplied by the anterior branch of the mandibular nerve (V3), a division of the trigeminal nerve.
**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect because the lateral pterygoid muscle primarily depresses the mandible, rather than protruding it. The muscle of protrusion is the digastric muscle, which is innervated by the mylohyoid nerve (a branch of the mandibular nerve).
**Option B:** This statement is incorrect because the lateral pterygoid muscle does not arise from the infratemporal fossa. While the superior head does originate from the infratemporal surface of the greater wing of the sphenoid bone, the infratemporal fossa is a larger anatomical space that contains several muscles and nerves.
**Option C:** This statement is incorrect because the lateral pterygoid muscle is not bipolar. It has two heads, but they converge to form a single tendon that inserts into the mandible.
**Option D:** This statement is incorrect because the lateral pterygoid muscle is not supplied by the facial nerve. The facial nerve (cranial nerve VII) primarily innervates muscles of facial expression, including the muscles of the face and the stapedius muscle in the middle ear.
**Clinical Pearl / High-Yield Fact**
The lateral pterygoid muscle is a key muscle in the movement of the jaw and plays a crucial role in the opening and closing of the mouth. Damage to this muscle can result in difficulty in moving the jaw, leading to symptoms such as temporomandibular joint pain and limited mouth opening.
**Correct Answer: B. Arise from infra temporal fossa & lateral pterygoid plate**