Lateral pterygoid muscle 2194292 222072489 2008-06-27T12:46:12Z Slodave 301776 +iw {{Infobox Muscle | Name = {{PAGENAME}} | Latin = m. pterygoideus lateralis, m. pterygoideus externus | GraySubject = 109 | GrayPage = 386 | Image = Musculuspterygoideuslateralis.png | Caption = 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.) | Image2 = Gray311.png | Caption2 = Sagittal section of the articulation of the mandible. (Labeled as "pterygoideus externus", visible in gray at bottom right.) | Origin = [[Great wing of sphenoid]] and [[pterygoid plate]] | Insertion = [[Condyle of mandible]] | Blood = [[pterygoid branches of maxillary artery]] | Nerve = [[lateral pterygoid nerve]] from the [[mandibular nerve]] | Action = [[Depression (kinesiology)|depresses]] [[mandible]] | Antagonist = | MeshName = Pterygoid+Muscles | MeshNumber = A02.633.567.600.700 | DorlandsPre = m_22 | DorlandsSuf = 12550292 | }} The '''lateral pterygoid''' (or '''external pterygoid''') is a muscle of [[mastication]] 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 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]]. ==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 pterygoid muscle|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. ==Additional images== <gallery> Image:Gray146.png|Sphenoid bone. Anterior and inferior surfaces. Image:Gray177.png|Mandible. Inner surface. Side view. Image:Gray510.png|Plan of branches of internal maxillary artery. Image:Gray778.png|Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion. </gallery> ==External links== * {{GPnotebook|-73793457}} * {{MuscleLoyola|lpte}} * {{NormanAnatomy|lesson4}} ({{NormanAnatomyFig|musclesofmastication2}}) * {{MedicalMnemonics|70|||}} * {{RocheLexicon|25420.000-1}} * [http://iris3.med.tufts.edu/medgross/hd5ans.htm Cross section at tufts.edu] {{Muscles of head}} {{muscle-stub}} [[Category:Muscles of the head and neck]] [[ar:عضلة جناحية وحشية]] [[de:Musculus pterygoideus lateralis]] [[fr:Muscle ptérygoïdien latéral]] [[it:Muscolo pterigoideo esterno]] [[hu:Musculus pterygoideus lateralis]] [[nl:Musculus pterygoideus lateralis]] [[ja:外側翼突筋]] [[sl:Lateralna pterigoidna mišica]] [[sr:Спољашњи криласти мишић]] [[sh:Spoljašnji krilasti mišić]] [[fi:Ulompi siipilihas]]