Musculus pterygoideus externus

Lateral pterygoid muscle
File:Lateral pterygoid muscle.png Lateral pterygoid muscle (highlighted in red)
Details
Origin	Greater wing of sphenoid, Lateral pterygoid plate
Insertion	Condyloid process of the mandible
Artery	Pterygoid venous plexus
Nerve	Lateral pterygoid nerve from the mandibular nerve
Actions	Depresses and protracts the mandible; moves the mandible from side to side
Antagonist	Temporalis muscle, Masseter muscle, Medial pterygoid muscle
Identifiers
Latin	Musculus pterygoideus externus
TA98
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of muscle

The lateral pterygoid muscle (Musculus pterygoideus externus) is a muscle of mastication with two heads. It lies superior to the medial pterygoid muscle and is one of the muscles responsible for the movement of the mandible.

Structure

The lateral pterygoid muscle has two heads: the superior head and the inferior head. The superior head originates from the greater wing of the sphenoid bone, while the inferior head originates from the lateral pterygoid plate of the sphenoid bone. Both heads converge to insert into the condyloid process of the mandible.

Innervation

The muscle is innervated by the lateral pterygoid nerve, a branch of the mandibular nerve (the third division of the trigeminal nerve).

Blood Supply

The blood supply to the lateral pterygoid muscle is provided by the pterygoid venous plexus.

Function

The primary function of the lateral pterygoid muscle is to depress and protract the mandible. It also assists in the side-to-side movement of the mandible, which is essential for mastication (chewing).

Clinical Significance

Dysfunction of the lateral pterygoid muscle can lead to temporomandibular joint disorder (TMD), which can cause pain and difficulty in moving the jaw.

See Also

• Medial pterygoid muscle
• Temporalis muscle
• Masseter muscle
• Mandibular nerve
• Mastication