Superior Constrictorweakest, but most complex of the threeforms nasopharyngeal and upper oropharyngeal wallsOrigin – sphenoid, mandible, pterygomandibular ligamentCourse – posterior, them medialInsert – midline rapheAction – may contribute to velopharyngeal closurePharynx—Middle Constrictorsomewhat fan shapedOrigin – hyoid boneCourse – fan out posteriorly and mediallyInsert – midline rapheAction – modify diameter of pharynxPharynx—Inferior Constrictorthickest and strongestOrigin – most from thyroid cartilageCourse – fan out posteriorly and mediallyInsert – midline rapheAction – modify pharynxcontribute to upper esophageal sphincter (see cricopharyngeus)Pharynx—Cricopharyngeuspart of Inferior constrictormuscular component of upper esophageal sphincterOrigin – cricoid cartilageCourse – fan out posteriorly and mediallyInsert – midline rapheAction – open and close UESPharynx—StylopharyngeusOrigin – styloid process of temporal boneCourse – inferior, entering between superior and middle constrictorInsert – blend with constrictors, with some fibers inserting on thyroid cartilageAction – elevate and dilate pharynxMuscles of Masticationact on mandibleprimary mandibular movements are elevation (raising) and depression (lowering)also, protrusion, retraction, lateral motionmuscles grouped into elevators and depressorsDepressorspaired muscle, each consisting of 2 fleshy belliesAnterior BellyOrigin ‐ lower border of mandible, near midlineCourse – 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 – with hyoid fixed, depress mandibleDepressors—Mylohyoidthin 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 – effect on mandible probably minimal, but could assist in loweringDepressors—Geniohyoidpaired cylindrical muscle located just superior to mylohyoidOrigin – lower part of mental symphysisCourse – inferior and posteriorInsertion – body of hyoid boneAction – with hyoid fixed, may assist in jaw loweringDepressors—Lateral Pterygoidalso known as External pterygoidOrigin – greater wing of sphenoidand lateral pterygoid plateCourse – horizontal and posteriorInsert – condyle of mandibleAction – protrude mandible by sliding condyle down and forwardunilateral contraction produces grinding actionCSD 3112 1st Edition Lecture 29Outline of Last Lecture I. Velopharyngeal MechanismII. VP Musclesa. Tensor VeliPalatinib. LevatorVeliPalatinic. Musculus Uvulaed. Palatoglossuse. PalatopharyngeusOutline of Current Lecture III. Pharynxa. Superior Constrictorb. Middle Constrictorc. Inferior Constrictord. Cricopharyngeuse. StylopharyngeusIV. Muscles of Masticationa. Depressorsi. Mylohyoidii. Geniohyoidiii. Lateral PterygoidCurrent Lecture These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Superior Constrictor- weakest, but most complex of the three- forms nasopharyngeal and upper oropharyngeal walls- Origin – sphenoid, mandible, pterygomandibular ligament- Course – posterior, them medial- Insert – midline raphe- Action – may contribute to velopharyngeal closure Pharynx—Middle Constrictor- somewhat fan shaped- Origin – hyoid bone- Course – fan out posteriorly and medially - Insert – midline raphe- Action – modify diameter of pharynx Pharynx—Inferior Constrictor - thickest and strongest- Origin – most from thyroid cartilage- Course – fan out posteriorly and medially- Insert – midline raphe- Action – modify pharynxo contribute to upper esophageal sphincter (see cricopharyngeus) Pharynx—Cricopharyngeus- part of Inferior constrictor- muscular component of upper esophageal sphincter- Origin – cricoid cartilage- Course – fan out posteriorly and medially- Insert – midline raphe- Action – open and close UES Pharynx—Stylopharyngeus- Origin – styloid process of temporal bone- Course – inferior, entering between superior and middle constrictor- Insert – blend with constrictors, with some fibers inserting on thyroid cartilage- Action – elevate and dilate pharynx Muscles of Mastication- act on mandible- primary mandibular movements are elevation (raising) and depression (lowering)- also, protrusion, retraction, lateral motion- muscles grouped into elevators and depressors Depressors- paired muscle, each consisting of 2 fleshy bellies- Anterior Bellyo Origin ‐ lower border of mandible, near midlineo Course – inferior and posterioro Insertion – lesser horn of hyoid, via intermediate tendon- Posterior Belly- Origin – mastoid process of temporal boneo Course – inferior and anterioro Insertion – lesser horn of hyoid, via intermediate tendono Action – with hyoid fixed, depress mandible Depressors—Mylohyoid- thin sheet of muscle fibers forming muscular floor of mouth- Origin – inner surface of mandible from mental symphysis to last molar- Course – inferior and medial- Insertion – with fibers from other side along midline raphe ‐ posterior fibers insert onto body of hyoid bone- Action – effect on mandible probably minimal, but could assist in lowering Depressors—Geniohyoid- paired cylindrical muscle located just superior to mylohyoid- Origin – lower part of mental symphysis- Course – inferior and posterior- Insertion – body of hyoid bone- Action – with hyoid fixed, may assist in jaw loweringDepressors—Lateral Pterygoid- also known as External pterygoid- Origin – greater wing of sphenoid- and lateral pterygoid plate- Course – horizontal and posterior- Insert – condyle of mandible- Action – protrude mandible by sliding condyle down and forward o unilateral contraction produces grinding