- Lateral pterygoid muscle
Infobox Muscle
Name = PAGENAME
Latin = m. pterygoideus lateralis, m. pterygoideus externus
GraySubject = 109
GrayPage = 386
| Caption = The Pterygoidei; the
zygomatic arch and a portion of theramus of themandible have been removed. (Labeled as "pterygoideus externus", visible in pink at center.)
| Caption2 = Sagittal section of the articulation of the mandible. (Labeled as "pterygoideus externus", visible in gray at bottom right.)
Origin =Great wing of sphenoid andpterygoid plate
Insertion =Condyle of mandible
Blood =pterygoid branches of maxillary artery
Nerve =lateral pterygoid nerve from themandibular nerve
Action = depressesmandible
Antagonist =
MeshName = Pterygoid+Muscles
MeshNumber = A02.633.567.600.700
DorlandsPre = m_22
DorlandsSuf = 12550292
The lateral pterygoid (or external pterygoid) is a muscle ofmastication with two heads.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 thelateral pterygoid plate .Both heads insert onto the
pterygoid fovea under thecondyloid process of themandible ; thearticular disc andfibrous capsule of theTMJ .Innervation
The lateral pterygoid nerve - The mandibular branch of the fifth cranial nerve, the
trigeminal nerve , innervates the lateral pterygoid muscle.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 andgeniohyoid muscles.
=AdditionalExternal links
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* (NormanAnatomyFig|musclesofmastication2)
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* [http://iris3.med.tufts.edu/medgross/hd5ans.htm Cross section at tufts.edu]
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