Extrinsic Musclesone􏰁attachment􏰁to􏰁structures􏰁outside􏰁larynxie) hyoid boneresponsible􏰁for􏰁support􏰁and􏰁fixation􏰁of􏰁larynx􏰁in􏰁neckSuprahyoid􏰁and􏰁InfrahyoidSuprahyoid (lies above the hyoid bone)DigastricStylohyoidMylohyoid 􏰀GeniohyoidDigastricpaired􏰁muscle,􏰁each􏰁consisting􏰁of􏰁2􏰁fleshy􏰁 belliesAnterior􏰁BellyOrigin-lower􏰁border􏰁of􏰁mandible,􏰁near􏰁midline Course􏰁– inferior􏰁and􏰁posteriorInsertion􏰁– lesser􏰁horn􏰁of􏰁hyoid,􏰁via􏰁intermediate􏰁tendonPosterior􏰁BellyOrigin􏰁– mastoid process􏰁of􏰁temporal boneCourse􏰁– inferior􏰁and􏰁anteriorInsertion􏰁– lesser􏰁horn􏰁of􏰁hyoid,􏰁via􏰁 intermediate􏰁tendonAction􏰁– raise􏰁hyoid􏰁boneIntermediate tendon take anterior and posterior belly to connect with hyoidElevated hyoidMandible has to be fixedStylohyoidlong􏰁slender􏰁muscle􏰁lying􏰁just􏰁superficial􏰁to􏰁 posterior􏰁belly􏰁of􏰁digastricOrigin􏰁– styloid process􏰁of􏰁temporal􏰁boneCourse􏰁– parallel􏰁to􏰁posterior􏰁belly􏰁of􏰁 digastricInsertion􏰁– body􏰁of􏰁hyoid􏰁bone􏰁at􏰁junction􏰁 with􏰁greater􏰁hornAction􏰁– draw􏰁hyoid􏰁bone􏰁superiorly􏰁and􏰁 posteriorly*Elevate hyoid posteriorly and superiorlyMylohyoidthin􏰁sheet􏰁of􏰁muscle􏰁fibers􏰁forming􏰁muscular􏰁 floor􏰁of􏰁mouthOrigin􏰁– inner􏰁surface􏰁of􏰁mandible􏰁from􏰁 mental􏰁symphysis to􏰁last􏰁molarCourse􏰁– inferior􏰁and􏰁medialInsertion􏰁– with􏰁fibers􏰁from􏰁other􏰁side􏰁along􏰁 midline􏰁raphe 􏰂 posterior􏰁fibers􏰁insert􏰁onto􏰁 body􏰁of􏰁hyoid􏰁boneAction􏰁– elevate􏰁hyoid􏰁bone,􏰁floor􏰁of􏰁mouth,􏰁 tongue*DigastricMylohyoidGeniohyoid (deepest)Geniohyoidpaired􏰁cylindrical􏰁muscle􏰁located􏰁just􏰁 superior􏰁to􏰁mylohyoid􏰀 Origin􏰁– lower􏰁part􏰁of􏰁mental􏰁symphysis􏰀 Course􏰁– inferior􏰁and􏰁posterior􏰀 Insertion􏰁– body􏰁of􏰁hyoid􏰁bone􏰀 Action􏰁– with􏰁mandible􏰁fixed,􏰁raises􏰁hyoid􏰁 bone􏰁superiorly􏰁and􏰁anteriorlyInfrahyoidSternohyoidOmohyoidSternothyroid 􏰀ThyrohyoidSternohyoidflat􏰁muscle􏰁lying􏰁on􏰁anterior􏰁surface􏰁of􏰁neck􏰀 Origin􏰁– posterior􏰁surface􏰁of􏰁manubrium of􏰁sternum􏰁and􏰁medial􏰁end􏰁of􏰁clavicle􏰀 Course􏰁– superior􏰀 Insertion􏰁– body􏰁of􏰁hyoid􏰁bone􏰀 Action􏰁– draws􏰁hyoid􏰁inferiorlyOmohyoidlong,􏰁narrow􏰁two􏰂bellied􏰁muscle􏰁on􏰁antero􏰂 lateral􏰁surface􏰁of􏰁neck􏰀 Inferior􏰁Belly􏰀 Origin􏰁– upper􏰁border􏰁of􏰁scapula􏰀 Course􏰁– horizontally,􏰁medially􏰀 Insertion􏰁– intermediate􏰁tendon,􏰁under􏰁sternocleidomastoideus􏰀 Superior􏰁Belly 􏰀 Origin􏰁– intermediate􏰁tendon 􏰀 Course􏰁– superior􏰁and􏰁medial 􏰀 Insertion􏰁– greater􏰁horn􏰁of􏰁hyoid􏰁bone􏰀 Action􏰁– depress􏰁hyoid􏰁boneSternothyroidlong􏰁slender􏰁muscle􏰁on􏰁anterior􏰁surface􏰁of􏰁 neck􏰀 Origin􏰁– manubrium of􏰁sternum􏰁and􏰁first􏰁 costal􏰁cartilage􏰀 Course􏰁– superior􏰁and􏰁slightly􏰁lateral􏰀 Insertion􏰁– thyroid􏰁cartilage􏰁lamina􏰀 Action􏰁– may􏰁draw􏰁thyroid􏰁cartilage􏰁inferiorly*underneath sternohyoidpulls down thyroid cartilageThyrohyoidappears􏰁as􏰁superiorly􏰁directed􏰁extension􏰁of􏰁 sternothyroid􏰀 Origin􏰁– thyroid􏰁cartilage􏰁lamina􏰀 Course􏰁– superior􏰀 Insertion􏰁– greater􏰁horn􏰁of􏰁hyoid􏰁bone􏰀 Action􏰁– decreases􏰁distance􏰁between􏰁thyroid􏰁 cartilage􏰁and􏰁hyoid􏰁boneIntrinsic Muscleslargely􏰁responsible􏰁for􏰁control􏰁of􏰁sound􏰁productioncategorized􏰁by􏰁their􏰁effect􏰁on􏰁shape􏰁of􏰁glottis􏰁and􏰁on􏰁vibratory􏰁behavior􏰁of􏰁vocal􏰁foldsabductorsadductorstensorsrelaxorsalways􏰁act􏰁in􏰁pairsadjust􏰁larynx􏰁in􏰁two􏰁waysMedial􏰁compressionforce􏰁with􏰁which􏰁vocal􏰁folds􏰁brought􏰁togetherLongitudinal􏰁tension 􏰃stretching􏰁force*can change vocal characteristic by both bringing vocal folds together to squeezing them togethershorten = more tenseThyroarytenoidThyrovocalis􏰁(vocalis) 􏰀ThyromuscularisCricothyroidPosterior􏰁Cricoarytenoid 􏰀Lateral􏰁CricoarytenoidInterarytenoidsTransverse 􏰀ObliqueThyroarytenoidtensor/relaxormakes􏰁up􏰁main􏰁mass􏰁of􏰁vibrating􏰁vocal􏰁foldsconsists􏰁of􏰁two􏰁muscle􏰁massesVocalis (Thyrovocalis)- portion􏰁just􏰁 lateral􏰁to􏰁vocal􏰁ligamentThyromuscularis- lateral􏰁to􏰁vocalisVocalisthought􏰁to􏰁be􏰁vibrating􏰁mass􏰁of vocal􏰁folds􏰀 Origin􏰁– posterior􏰁border􏰁of􏰁 thyroid􏰁angle􏰀 Course􏰁– posterior􏰀 Insertion􏰁– vocal􏰁process􏰁and􏰁 lateral􏰁surface􏰁of􏰁arytenoid􏰁 cartilagesThyromuscularis􏰀 Origin􏰁– thyroid􏰁lamina,􏰁lateral􏰁 to􏰁vocalis􏰀 Course􏰁– posterior,􏰁parallel􏰁to􏰁 vocalis􏰀 Insertion􏰁– anterolateral􏰁surface􏰁 and􏰁muscular􏰁process􏰁of􏰁 arytenoidsAction principle􏰁function􏰁is􏰁regulator􏰁of􏰁 longitudinal􏰁 tension􏰀 when􏰁not􏰁opposed􏰁by􏰁other􏰁muscles,􏰁 may􏰁shorten􏰁and􏰁relax􏰁vocal􏰁folds􏰀 may􏰁assist􏰁in􏰁closing􏰁glottis􏰁by􏰁drawing􏰁 muscular􏰁process􏰁of􏰁arytenoid forward􏰀 when􏰁opposed􏰁by􏰁other􏰁muscles,􏰁tenses􏰁 vocal􏰁foldsCricothyroid(vocal fold) tensorfan􏰁shaped􏰁muscle􏰁consisting􏰁of􏰁vertical􏰁(pars􏰁recta)􏰁and􏰁oblique􏰁(pars􏰁oblique)􏰁bundles􏰀 Origin􏰁– anterolateral arch􏰁of􏰁cricoid cartilage􏰀 Pars􏰁recta (vertically oriented)Course􏰁– superiorInsertion􏰁– lower􏰁margin􏰁of􏰁thyroid lamina􏰀 Pars􏰁oblique (obliquely oriented)Course􏰁– superior􏰁and􏰁posteriorInsertion􏰁– inferior􏰁cornu of􏰁thyroid cartilagePars􏰁rectareduces􏰁distance􏰁between􏰁cricoid􏰁arch􏰁and􏰁thyroid􏰁laminacauses􏰁rotation􏰁about􏰁cricothyroid jointPars􏰁obliqueantero􏰂posterior􏰁sliding􏰁at cricothyroid􏰁jointresult􏰁is􏰁increase􏰁in􏰁distance􏰁between