Head and Neck Anatomy III PDF

Lecture 6: Muscles of Mastication and Soft Palate 1. Names of each of the muscles in both regions Muscles of Mastication: o Masseter o Temporalis o Medial Pterygoid o Lateral pterygoid...

Lecture 6: Muscles of Mastication and Soft Palate 1. Names of each of the muscles in both regions Muscles of Mastication: o Masseter o Temporalis o Medial Pterygoid o Lateral pterygoid Palatal Muscles (People Prefer Lifting Tall Umbrellas): o Palatoglossus o Palatopharyngeal o Levator Veli Palatini o Tensor Veli Palatini o Uvular Muscles 2. Know the location, function, and innervation of each of the muscles. - Origin = where muscle starts - Insertion = where the muscle ends Muscles of Mastication Muscle Location Function Innervation Masseter Origin: zygomatic arch (cheekbone) Elevation of the mandible Masseteric branch of CNV3 (mandibular Insertion: lateral aspect of mandibular (closes the jaw) division of trigeminal nerve) ramus Temporalis Origin: temporal fossa Resting tonus (when we rest Deep temporal nerve branches of CNV3 Insertion: coronoid process of the jaw hangs) mandible Elevation Retrusion (moving backward) Medial Pterygoid Lies on medial aspect of the Elevation Pterygoid nerve branches of CNV3 mandibular ramus. Origin: pterygoid fossa of sphenoid bone Insertion: angle of mandible Lateral Pterygoid Within infratemporal fossa Protrusion (forward Pterygoid nerve branches of CNV3 movement) *Only horizontal muscle Has two heads: of mastication* - Superior head origin: greater Contralateral excursion wing of the sphenoid bone (opposite side to side *Helps in moving jaw - Inferior head origin: lateral movement of mandible) forward (protrusion) and pterygoid plate - If muscle on left is side to side (contralateral contracting, it excursion) * Insertion: pterygoid fovea of the causes the mandible condylar neck of the mandible and to move to the right. TMJ capsule  Palatal Muscles (soft palate) Muscles Origin Insertion Action Innervation Palatoglossus Median palatine raphe Lateral margin of Elevates and arches Pharyngeal plexus of vagus nerve (think palate and tongue) tongue tongue. (CN X) Depresses palate toward tongue. *Lowering soft palate and raising the tongue Palatopharyngeal Soft palate Laryngopharynx Moves palate Pharyngeal plexus of vagus nerve (think palate and pharynx) posteroinferiorly (back (CN X) Thyroid cartilage and downward) Moves posterior pharyngeal wall anterosuperiorly (front and upward) Levator Veli Palatini Temporal bone Median palatine Raises soft palate to Pharyngeal plexus of vagus nerve (think elevator) raphe contact the posterior (CN X) pharyngeal wall. *Elevates the soft palate Tensor Veli Palatini Auditory tube Tendon hooks Tenses and slightly Pterygoid nerve branches of under hamulus and raises soft palate CNV3 Spine of sphenoid inserts into median palatine raphe Uvular Muscles Posterior spine of hard Uvula Elevates and retracts Pharyngeal plexus of vagus nerve palate (posterior nasal uvula to closely adapt (CN X) spine) the soft palate to the posterior pharyngeal wall 3. Understand the "outliers" (e.g. Which muscle in the group of muscles has a different innervation or unique function) o Lateral Pterygoid Only muscle for protrusion (moving mandible forward) and contralateral excursion (side to side movement) o Temporalis Only muscle for resting tonus and retrusion (moving backward) o Tensor Veli Palatini Pterygoid nerve branches of CNV3 (instead of CN X)