Lateral pterygoid muscle

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Lateral pterygoid muscle

The Pterygoidei; the zygomatic arch and a portion of the ramus of the mandible have been removed. (Labeled as "pterygoideus externus", visible in pink at center.)

Sagittal section of the articulation of the mandible. (Labeled as "pterygoideus externus", visible in gray at bottom right.)
Latin	m. pterygoideus lateralis, m. pterygoideus externus
Gray's	subject #109 386
Origin	Great wing of sphenoid and pterygoid plate
Insertion	Condyle of mandible
Artery:	pterygoid branches of maxillary artery
Nerve:	lateral pterygoid nerve from the mandibular nerve
Action:	depresses mandible
MeSH	Pterygoid+Muscles
Dorlands /Elsevier	m_22/12550292

The lateral pterygoid (or external pterygoid) is a muscle of mastication with two heads.

1 Origin and insertion
2 Innervation
3 Function
4 Additional images
5 External links

[edit] Origin and insertion

The upper/superior head originates on the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, and the lower/inferior head on the lateral surface of the lateral pterygoid plate.

Both heads insert onto the pterygoid fovea under the condyloid process of the mandible; the articular disc and fibrous capsule of the TMJ.

[edit] Innervation

The lateral pterygoid nerve - The mandibular branch of the fifth cranial nerve, the trigeminal nerve, innervates the lateral pterygoid muscle.

[edit] Function

It acts to lower the mandible, open the jaw, and help the medial pterygoids in moving the jaw from side to side (mastication).

Unlike the other three muscles of mastication, the lateral pterygoid is the only one that opens the jaw, or depresses the mandible. At the beginning of this action it is assisted by the digastric, mylohyoid and geniohyoid muscles.

[edit] Additional images

Sphenoid bone. Anterior and inferior surfaces.

Mandible. Inner surface. Side view.

Plan of branches of internal maxillary artery.

Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion.

[edit] External links

v • d • e

List of muscles of head and neck: the head

Extraocular (CN III, IV, VI)

oblique (inferior, superior) - rectus (superior, inferior, medial, lateral) - levator palpebrae superioris (superior tarsal)

Mastication (CN V3)

masseter - temporalis - pterygoid (lateral, medial)

Facial (CN VII)

Mouth/throat (CN IX, X, XI)
(except TVP=V3)

Soft palate	veli palatini (tensor, levator) - musculus uvulae - palatopharyngeus (to pharnyx) - palatoglossus (to tongue)

Pharynx	pharyngeal constrictor (superior, middle, inferior) - longitudinal (stylopharyngeus, salpingopharyngeus)

Larynx	cricothyroid - cricoarytenoid (posterior, lateral) - arytenoid (oblique arytenoid/aryepiglottic, transverse arytenoid) - thyroarytenoid (vocal, thyroepiglottic)