Muscles of the Scalp

MusclesMuscles ofof thethe scalpscalp OccipitoOccipito‐‐frontalisfrontalis •• OriginOrigin:: occipitaloccipital bellybelly fromfrom thethe highesthighest nuchalnuchal line. line. FrontalFrontal bellybelly fromfrom thethe skinskin andand superficialsuperficial fasciafascia ofof thethe eyebrowseyebrows.. •• InsertionInsertion:: bothboth belliesbellies areare insertedinserted intointo thethe epicranialepicranial aponeurosis aponeurosis.. •• NerveNerve supplysupply:: occipitaloccipital bellybelly fromfrom posteriorposterior auricularauricular branchbranch ofof facialfacial nervenerve andand frontalfrontal bellybelly fromfrom temporaltemporal branchbranch ofof facialfacial nervenerve.. •• ActionAction:: movesmoves thethe superficialsuperficial 33 layerslayers together,together, andand raisesraises thethe eyebrowseyebrows

MusclesMuscles ofof facialfacial expressionexpression •• PresentPresent inin thethe superficialsuperficial fasciafascia ofof thethe face.face. •• InsertedInserted intointo thethe skinskin ofof thethe face.face. •• RelatedRelated toto thethe threethree mainmain orificesorifices ofof thethe faceface (either(either sphincterssphincters oror dilator).dilator). •• MostMost importantimportant threethree are:are: 1.1. Orbicularis Orbicularis oculi. oculi. 2.2. Orbicularis Orbicularis oris. oris. 3.3. Buccinator. Buccinator.

OrbicularisOrbicularis oculi oculi •• HasHas threethree parts:parts: OrbitalOrbital part,part, palpebralpalpebral part part andand lacrimallacrimal part. part. •• OriginOrigin:: MedialMedial palpebralpalpebral ligament ligament andand adjoiningadjoining bones.bones. •• InsersionInsersion:: ¾¾ orbitalorbital partpart makesmakes aa looploop andand returnsreturns toto origin.origin. ¾¾ PalpebralPalpebral part part:: laterallateral papebralpapebral raphe. raphe. ¾¾ LacrimalLacrimal part: part: lacrimallacrimal sac. sac. •• NerveNerve supplysupply:: facialfacial nerve.nerve. •• ActionAction:: ¾¾ orbitalorbital partpart:: forcedforced closureclosure ofof thethe eyelidseyelids (protection).(protection). ¾¾ PalpebralPalpebral part: part: lightlight closureclosure ofof eyelidseyelids (blinking).(blinking). ¾¾ LacrimalLacrimal part: part: dilatesdilates thethe lacrimallacrimal sac sac (to(to draindrain tears).tears).

OrbicularisOrbicularis oris oris •• EncirclesEncircles thethe oraloral orificeorifice withinwithin thethe lips.lips. •• OriginOrigin:: Maxilla,Maxilla, mandiblemandible andand skin.skin. •• InsersionInsersion:: encirclesencircles thethe oraloral orificeorifice •• NerveNerve supplysupply:: buccalbuccal and and mandibularmandibular branchesbranches ofof facialfacial nerve.nerve. •• ActionAction:: CompressesCompresses thethe lipslips togethertogether (kissing,(kissing, blowingblowing andand etcetc ….)….)

BuccinatorBuccinator •• OriginOrigin:: outerouter surfacesurface ofof thethe alveolaralveolar marginsmargins ofof maxillamaxilla andand mandiblemandible oppositeopposite thethe molarmolar teethteeth andand pterygomandibularpterygomandibular raphe. raphe. •• InsersionInsersion:: •• UpperUpper fibersfibers enterenter thethe upperupper liplip toto bebe attachedattached toto fibersfibers ofof oppositeopposite side.side. •• LowerLower fibersfibers enterenter thethe lowerlower liplip toto bebe attachedattached toto fibersfibers ofof oppositeopposite side.side. •• MiddleMiddle fibersfibers decussatedecussate atat thethe angleangle ofof thethe mouthmouth andand formform thethe orbicularisorbicularis oris oris muscle. muscle. •• NerveNerve supplysupply:: buccalbuccal branch branch ofof facialfacial nerve.nerve. •• ActionAction:: CompressesCompresses thethe cheekscheeks lipslips againstagainst thethe teeth.teeth. •• ThisThis musclemuscle isis piercedpierced byby thethe ductduct ofof thethe parotidparotid salivarysalivary gland.gland.

MusclesMuscles ofof masticationmastication 1.1.Temporalis. Temporalis. 2.2.Masseter. Masseter. 3.3.Lateral Lateral pterygoid.pterygoid. 4.4.Medial Medial pterygoid.pterygoid.

Temporalis •• OriginOrigin:: FloorFloor ofof temporaltemporal fossafossa and and deepdeep surfacesurface ofof temporaltemporal fascia.fascia. •• InsertionInsertion::Coronoid Coronoid process process andand anterioranterior borderborder ofof ramusramus of of mandible.mandible. •• NerveNerve supplysupply::Deep Deep temporaltemporal nervesnerves (from(from andand thethe anterioranterior divisiondivision ofof mandibularmandibular nerve). nerve). •• ActionAction:: ElevationElevation andand retractionretraction ofof thethe mandible.mandible.

Masseter •• OriginOrigin:: LowerLower borderborder andand innerinner surfacesurface ofof thethe zygomaticzygomatic arch. arch. •• InsertionInsertion::Lateral Lateral aspectaspect ofof thethe ramusramus of of thethe mandible.mandible. •• NerveNerve supplysupply::anterior anterior divisiondivision ofof thethe mandibularmandibular nerve. nerve. •• ActionAction:: ElevationElevation andand protractionprotraction ofof thethe mandible.mandible.

Lateral pterygoid •• OriginOrigin:: UpperUpper headhead:: fromfrom thethe infratemporalinfratemporal surfacesurface ofof thethe greatergreater wingwing ofof sphenoidsphenoid bone.bone. LowerLower headhead:: fromfrom thethe laterallateral surfacesurface ofof thethe laterallateral pterygoidpterygoid plate plate.. •• InsertionInsertion:: anterioranterior aspectaspect ofof thethe neckneck ofof thethe mandiblemandible andand thethe articulararticular disc disc ofof thethe temporo-mandibulartemporo-mandibular joint. joint. •• NerveNerve supplysupply:: anterioranterior divisiondivision ofof thethe mandibularmandibular nerve. nerve. •• ActionAction:: pullspulls thethe headhead ofof mandiblemandible forwardforward duringduring openingopening ofof thethe mouthmouth (helps(helps inin depressiondepression ofof mandible),mandible), protractsprotracts thethe mandiblemandible andand sideside toto sideside movesmoves itit (chewing).(chewing).

Medial pterygoid •• OriginOrigin:: SuperficialSuperficial headhead:: fromfrom thethe maxillarymaxillary tuberositytuberosity.. DeepDeep headhead:: fromfrom thethe medialmedial surfacesurface ofof thethe laterallateral pterygoidpterygoid plate. plate. •• InsertionInsertion::medial medial surfacesurface ofof thethe angleangle ofof thethe mandiblemandible.. •• NerveNerve supplysupply:: MainMain trunktrunk ofof thethe mandibularmandibular nerve. nerve. •• ActionAction:: helpshelps inin elevationelevation ofof mandible,mandible, protractionprotraction ofof thethe mandiblemandible andand sideside toto sideside movementmovement (chewing).(chewing).

Sterno‐cleidomastoid muscle •• OriginOrigin:: upperupper borderborder ofof manubriummanubrium sterni sterni and and medialmedial thirdthird ofof upperupper surfacesurface ofof clavicle.clavicle. •• InsertionInsertion:: mastoidmastoid processprocess andand laterallateral thirdthird ofof superiorsuperior nuchalnuchal line. line. •• NerveNerve supplysupply:: SpinalSpinal accessoryaccessory nervenerve (motor)(motor) andand C2,3C2,3 (proprioceptive).(proprioceptive). •• ActionAction:: 1.1.Both Both musclesmuscles extendextend thethe atlanto-occipitalatlanto-occipital jointjoint andand flexflex thethe otherother cervicalcervical intervertebralintervertebral joints. joints. 2.2.One One musclemuscle turnsturns thethe headhead toto makemake thethe faceface lookslooks upwardupward andand toto thethe oppositeopposite side.side. 3.3.On On fixationfixation ofof thethe insertion,insertion, thethe musclemuscle actact asas accessoryaccessory musclemuscle ofof inspiration.inspiration.

Trapezius muscle •• OriginOrigin:: MedialMedial thirdthird ofof superiorsuperior nuchalnuchal line, line, externalexternal occipitaloccipital protuberance,protuberance, ligamentumligamentum nuchae,nuchae, 77thth cervicalcervical spinespine allall thethe thoracicthoracic spines.spines. •• InsertionInsertion:: laterallateral thirdthird ofof clavicle,clavicle, acromionacromion processprocess andand spinespine ofof scapula.scapula. •• NerveNerve supplysupply:: SpinalSpinal accessoryaccessory nervenerve (motor)(motor) andand C3,4C3,4 (proprioceptive).(proprioceptive). •• ActionAction:: 1.1.Both Both musclesmuscles extendextend thethe neck.neck. 2.2.Upper Upper fibersfibers ofof oneone sideside laterallateral flexflex thethe neck.neck. 3.3.Upper Upper fibersfibers elevateelevate thethe shoulder.shoulder. 4.4.Middle Middle fibersfibers retractretract thethe shoulder.shoulder. 5.5.Lower Lower fibersfibers depressdepress thethe shoulder.shoulder.

Platysma muscle •• OriginOrigin:: deepdeep fasciafascia ofof thethe upperupper partpart ofof thoraxthorax (covering(covering pectoralispectoralis majormajor andand deltoid).deltoid). •• InsertionInsertion:: lowerlower borderborder ofof thethe mandible.mandible. •• NerveNerve supplysupply:: CervicalCervical branchbranch ofof facialfacial nerve.nerve. •• ActionAction:: DepressionDepression ofof thethe mandiblemandible..

Splenius capitis muscle •• OriginOrigin:: 1.1.Lower Lower partpart ofof ligamentumligamentum nuchae. nuchae. 2.2.Upper Upper fourfour thoracicthoracic spines.spines. •• InsertionInsertion::mastoid mastoid processprocess andand outerouter partpart ofof superiorsuperior nuchalnuchal line line.. •• NerveNerve supplysupply::segmentalsegmental innervationinnervation from from thethe dorsaldorsal ramirami of of spinalspinal nervesnerves •• ActionAction:: ExtensionExtension ofof thethe neck.neck.

Levator scapulae muscle •• OriginOrigin:: TransverseTransverse processesprocesses ofof upperupper fourfour cervicalcervical vertebrae.vertebrae. •• InsertionInsertion::Upper Upper partpart ofof medialmedial borderborder ofof scapula.scapula. •• NerveNerve supplysupply:: C3,4C3,4 andand dorsaldorsal scapularscapular nervenerve (C5).(C5). •• ActionAction:: ElevationElevation ofof scapulascapula..

Scalenus medius muscle •• OriginOrigin:: TransverseTransverse processesprocesses ofof lowerlower sixsix cervicalcervical vertebraevertebrae (2-7).(2-7). •• InsertionInsertion:: UpperUpper surfacesurface ofof thethe firstfirst rib.rib. •• NerveNerve supplysupply::Segmental Segmental fromfrom thethe ventralventral ramirami of of cervicalcervical nerves.nerves. •• ActionAction:: ElevationElevation ofof firstfirst ribrib andand laterallateral flexionflexion thethe neck.neck.

Scalenus anterior muscle •• OriginOrigin:: TransverseTransverse processesprocesses ofof typicaltypical cervicalcervical vertebraevertebrae (3-6).(3-6). •• InsertionInsertion::Scalene Scalene tubercletubercle ofof thethe firstfirst rib.rib. •• NerveNerve supplysupply:: SegmentalSegmental fromfrom thethe ventralventral ramirami of of 44thth,, 55thth andand 66thth cervicalcervical nerves.nerves. •• ActionAction:: ElevationElevation ofof firstfirst ribrib andand laterallateral flexionflexion thethe neck.neck. Omohyoid muscle •• OriginOrigin:: 1.1.Superior Superior bellybelly fromfrom thethe inferiorinferior borderborder ofof bodybody ofof hyoidhyoid bone.bone. 2.2.Inferior Inferior bellybelly fromfrom upperupper borderborder ofof scapulascapula andand suprascapularsuprascapular ligament ligament.. •• InsertionInsertion:: toto thethe intermediateintermediate tendontendon whichwhich isis heldheld inin positionposition byby fibrousfibrous looploop toto thethe clavicle.clavicle. •• NerveNerve supplysupply:: AnsaAnsa cervicalis cervicalis (C1,2,3) (C1,2,3) •• ActionAction:: DepressionDepression ofof hyoidhyoid bone.bone.

Digastric muscle •• OriginOrigin:: 1.1.Posterior Posterior bellybelly fromfrom thethe medialmedial surfacesurface ofof mastoidmastoid processprocess (mastoid(mastoid notch).notch). 2.2.Anterior Anterior bellybelly fromfrom lowerlower borderborder ofof thethe bodybody ofof thethe mandiblemandible (digastric(digastric fossa). fossa). •• InsertionInsertion:: toto thethe intermediateintermediate tendontendon whichwhich isis heldheld inin positionposition byby fibrousfibrous looploop toto thethe hyoidhyoid bone,bone, thisthis tendontendon piercespierces thethe stylohyoidstylohyoid muscle muscle.. •• NerveNerve supplysupply:: posteriorposterior bellybelly fromfrom facialfacial nervenerve (with(with stylohyoid),stylohyoid), anterioranterior bellybelly fromfrom nervenerve toto mylohyoidmylohyoid from from mandibularmandibular (with (with mylohyoid)mylohyoid) •• ActionAction::Depression Depression ofof mandiblemandible andand elevationelevation ofof thethe hyoidhyoid bonebone..

Mylohyoid muscle •• OriginOrigin::Mylohyoid Mylohyoid line line ofof thethe innerinner surfacesurface ofof thethe mandible.mandible. •• InsertionInsertion:: UpperUpper surfacesurface ofof thethe bodybody ofof thethe hyoidhyoid bonebone andand inin thethe mylohyoidmylohyoid raphe. raphe. •• NerveNerve supplysupply:: NerveNerve toto mylohyoidmylohyoid from from inferiorinferior alveolaralveolar nervenerve fromfrom posteriorposterior divisiondivision ofof mandibularmandibular nerve. nerve. •• ActionAction:: thethe twotwo musclesmuscles 1.1.Support Support tonguetongue andand floorfloor ofof thethe mouth.mouth. 2.2.Elevate Elevate thethe floorfloor ofof thethe mouthmouth andand hyoidhyoid bonebone inin firstfirst stagestage ofof swallowing.swallowing. 3.3.Depress Depress thethe mandiblemandible andand openopen thethe mouth.mouth.

Stylohyoid muscle •• OriginOrigin:: StyloidStyloid process. process. •• InsertionInsertion::at at junctionjunction betweenbetween bodybody andand greatergreater hornhorn ofof hyoidhyoid bone,bone, itit isis piercedpierced byby thethe intermediateintermediate tendontendon ofof digastricdigastric muscle. muscle. •• NerveNerve supplysupply::Facial Facial nerve.nerve. •• ActionAction::Elevation Elevation ofof thethe hyoidhyoid bonebone..

Sternohyoid muscle •• OriginOrigin:: PosteriorPosterior surfacesurface ofof upperupper partpart ofof manubriummanubrium sterni sterni and and backback ofof medialmedial partpart ofof thethe clavicleclavicle.. •• InsertionInsertion:: lowerlower borderborder ofof thethe bodybody ofof hyoidhyoid bone.bone. •• NerveNerve supplysupply:: AnsaAnsa cervicalis cervicalis.. •• ActionAction:: DepressionDepression ofof thethe hyoidhyoid bone.bone. Omohyoid muscle •• OriginOrigin:: 1.1.Superior Superior bellybelly fromfrom thethe inferiorinferior borderborder ofof bodybody ofof hyoidhyoid bone.bone. 2.2.Inferior Inferior bellybelly fromfrom upperupper borderborder ofof scapulascapula andand suprascapularsuprascapular ligament ligament.. •• InsertionInsertion:: toto thethe intermediateintermediate tendontendon whichwhich isis heldheld inin positionposition byby fibrousfibrous looploop toto thethe clavicleclavicle.. •• NerveNerve supplysupply::Ansa Ansa cervicalis cervicalis (C1,2,3) (C1,2,3) •• ActionAction:: DepressionDepression ofof hyoidhyoid bone.bone. Sternothyroid muscle •• OriginOrigin:: PosteriorPosterior surfacesurface ofof upperupper partpart ofof manubriummanubrium sterni sterni and and backback ofof medialmedial partpart ofof thethe clavicle.clavicle. •• InsertionInsertion:: obliqueoblique lineline ofof laminalamina ofof thyroidthyroid cartilage.cartilage. •• NerveNerve supplysupply:: AnsaAnsa cervicalis. cervicalis. •• ActionAction:: DepressionDepression ofof thethe larynxlarynx andand thyroidthyroid cartilage.cartilage. Thyrohyoid muscle •• OriginOrigin:: obliqueoblique lineline ofof laminalamina ofof thyroidthyroid cartilage.cartilage. •• InsertionInsertion:: lowerlower borderborder ofof thethe bodybody ofof hyoidhyoid bone.bone. •• NerveNerve supplysupply:: FirstFirst cervicalcervical nervenerve throughthrough thethe hypoglossalhypoglossal nerve.nerve. •• ActionAction:: DepressionDepression ofof thethe hyoidhyoid bonebone andand elevationelevation ofof thyroidthyroid cartilagecartilage andand larynx.larynx. Digastric muscle •• OriginOrigin:: 1.1.Posterior Posterior bellybelly fromfrom thethe medialmedial surfacesurface ofof mastoidmastoid processprocess (mastoid(mastoid notch).notch). 2.2.Anterior Anterior bellybelly fromfrom lowerlower borderborder ofof thethe bodybody ofof thethe mandiblemandible (digastric(digastric fossa). fossa). •• InsertionInsertion:: toto thethe intermediateintermediate tendontendon whichwhich isis heldheld inin positionposition byby fibrousfibrous looploop toto thethe hyoidhyoid bone,bone, thisthis tendontendon piercespierces thethe stylohyoidstylohyoid muscle. muscle. •• NerveNerve supplysupply:: posteriorposterior bellybelly fromfrom facialfacial nervenerve (with(with stylohyoid),stylohyoid), anterioranterior bellybelly fromfrom nervenerve toto mylohyoidmylohyoid from from mandibularmandibular (with (with mylohyoid)mylohyoid) •• ActionAction:: DepressionDepression ofof mandiblemandible andand elevationelevation ofof thethe hyoidhyoid bonebone.. Stylohyoid muscle •• OriginOrigin:: StyloidStyloid process. process. •• InsertionInsertion:: atat junctionjunction betweenbetween bodybody andand greatergreater hornhorn ofof hyoidhyoid bone,bone, itit isis piercedpierced byby thethe intermediateintermediate tendontendon ofof digastricdigastric muscle. muscle. •• NerveNerve supplysupply:: FacialFacial nervenerve.. •• ActionAction:: ElevationElevation ofof thethe hyoidhyoid bone.bone.

Mylohyoid muscle •• OriginOrigin:: MylohyoidMylohyoid line line ofof thethe innerinner surfacesurface ofof thethe mandible.mandible. •• InsertionInsertion:: UpperUpper surfacesurface ofof thethe bodybody ofof thethe hyoidhyoid bonebone andand inin thethe mylohyoidmylohyoid raphe. raphe. •• NerveNerve supplysupply::Nerve Nerve toto mylohyoidmylohyoid from from inferiorinferior alveolaralveolar nervenerve fromfrom posteriorposterior divisiondivision ofof mandibularmandibular nerve. nerve. •• ActionAction:: thethe twotwo musclesmuscles 1.1.Support Support tonguetongue andand floorfloor ofof thethe mouth.mouth. 2.2.Elevate Elevate thethe floorfloor ofof thethe mouthmouth andand hyoidhyoid bonebone inin firstfirst stagestage ofof swallowing.swallowing. 3.3.Depress Depress thethe mandiblemandible andand openopen thethe mouth.mouth.

Geniohyoid muscle

•• OriginOrigin:: thethe inferiorinferior mentalmental spinespine (genial(genial tubercle)tubercle) behindbehind thethe symphysissymphysis menti menti of of thethe mandible.mandible. •• InsertionInsertion:: thethe anterioranterior surfacesurface ofof thethe bodybody ofof thethe hyoidhyoid bone.bone. •• NerveNerve supplysupply:: fromfrom thethe firstfirst cervicalcervical nervenerve throughthrough thethe hypoglossalhypoglossal nerve.nerve. •• ActionAction:: 1.1.Elevation Elevation andand protractionprotraction ofof thethe hyoidhyoid bone.bone. 2.2.Depression Depression ofof thethe mandible.mandible.