muscles of oral phase 1/15/25

Page 1: Swallowing Anatomy & Physiology

  • Course Title: SPATH 6544

  • Instructor: Heather Anderson, Ed.D., CCC-SLP

  • Focus: Muscle groups involved in the process of swallowing

Page 2: Anatomy of Swallowing

A. Oral Cavity

  • Function: Responsible for bolus containment and preparation

  • Components of Containment:

    1. Lips: Close after bolus intake.

    2. Cheeks: Maintain adequate tension to assist lip closure.

  • Bolus Preparation:

    1. Teeth: Facilitate mastication.

    2. Tongue: Acts as the driving force to initially propel the bolus.

    3. Gingival and Buccal Gutters: Channel the bolus towards the oropharynx.

    4. Soft Palate: Contacts the tongue to help form the bolus.

B. Oropharynx

  1. Oropharyngeal Propulsion Pump:

    • Involves the soft palate and lateral pharyngeal walls.

    • The base of the tongue plays a key role.

  2. Velopharyngeal Function:

    • Soft palate elevates as the tongue propels the bolus.

    • Tongue elevation is critical for successful propulsion.

C. Hypopharynx

  1. Muscular Propulsion:

    • Pharyngeal constrictors help to push the bolus down.

    • Piriform sinuses assist in directing the bolus.

    • Cricopharyngeal Function aids in the relaxation of the upper esophageal sphincter.

  2. Larynx:

    • Closure via the glottis, ventricular folds, and epiglottis.

    • Pharyngeal squeeze aids in pushing the bolus down.

    • Hyoid elevation is crucial during swallowing.

D. Esophagus

  1. Upper Esophageal Sphincter: Opens to allow bolus entry.

  2. Primary Peristaltic Wave: Muscle contractions that move the bolus through the esophagus.

  3. Secondary Peristaltic Wave: Helps clear any residual materials.

Page 3: Bolus Containment and Preparation Muscles of the Face

  • Key Muscles:

    • Orbicularis Oris

    • Levator Anguli Oris

    • Depressor Anguli Oris

    • Levator Labii Superioris

    • Depressor Labii Oris

    • Mentalis- protrudes lower lip and wrinkles chin

    • Zygomaticus Major and Minor

Page 4: Musculature of the Face

  • Face Muscles involved in Swallowing:

    • Frontalis

    • Zygomaticus Minor and Major

    • Zygomatic Arch

    • Orbicularis Oris (Superior and Inferior)

    • Masseter

    • Buccinator

    • Risorius- Joker muscles, draws corners outward

    • Depressor Labii Inferioris

    • Mentalis

    • Depressor Anguli Oris

    • Platysma- contributes to jaw retraction

Page 5: Bolus Preparation - Muscles of the Face

  • Muscles Involved:

    • Buccolabial muscles

    • Risorius Muscle

    • Buccinator- cheek muscles

    • Zygomaticus Major and Minor

    • Involvement of the Mandible (as the jaw structure for effective chewing)

Page 6: Muscle Actions and Innervation

  • Orbicularis Oris:

    • Origin: Neighboring muscles and skin around lips.

    • Insertion: Angles of the mouth.

    • Action: Closes, opens, protrudes, inverts and twists lips.

    • Nerve: Facial.

  • Zygomaticus Major:

    • Origin: Zygomatic bone.

    • Insertion: Orbicularis oris.

    • Action: Draws upper lip upward and backward.

    • Nerve: Facial.

  • Levator Labii Superioris:

    • Origin: Below infraorbital foramen in maxilla.

    • Insertion: Orbicularis oris.

    • Action: Elevates upper lip.

    • Nerve: Facial.

  • Other muscles detailed for their origins, insertions, nerves, and actions include: Depressor Anguli Oris, Depressor Labii Inferioris, Mentalis, Risorius, and Buccinator.

Page 7: Major Muscles of Mastication

Key Muscles Involved in Chewing

  • Mandibular Elevation involves:

    1. Temporalis

    2. Masseter

    3. Medial and Lateral Pterygoid (Elevation and Depression) (Corbin-Lewis & Sciortino, 2015)

Page 8: Muscles of Mastication

  • Temporalis:

    • Origin: Temporal fossa of skull. (temples)

    • Insertion: Ramus and coronoid process of mandible.

    • Nerve: Trigeminal.

    • Action: Elevates or retracts mandible.

  • Masseter:

    • Origin: Zygomatic arch.

    • Insertion: Ramus of mandible.

    • Nerve: Trigeminal.

    • Action: Elevates or closes jaw.

  • Medial Pterygoid:

    • Origin: Palatine bone, pterygoid plate.

    • Insertion: Ramus of mandible.

    • Nerve: Trigeminal.

    • Action: Elevates or closes jaw.

  • Lateral Pterygoid:

    • Origin: Great wing of sphenoid.

    • Insertion: Neck of condyle of mandible.

    • Nerve: Trigeminal.

    • Action: Depressor or opener of mandible; permits side-to-side movement.

Page 9: Visual Reference - Muscles of the Face KNOW THIS FOR TEST she winked!!!

  • Depicts muscles involved in mastication and their locations: Temporalis, Masseter, Buccinator & Orbicularis Oris. know what they all do

Page 10: Chewing - Overview

  • General review of the muscles involved in mastication and their functions.

Page 11: Additional Visual Aids

  • Further illustrations and diagrams for understanding muscle actions during swallowing and chewing.

Page 12: Bolus Formation and Manipulation - Intrinsic Tongue Muscles

  • Muscles Detailed:

    • Superior Longitudinal

    • Inferior Longitudinal

    • Transverse

    • Vertical

  • Roles: Each muscle group aids in manipulating the bolus for swallowing.

    • Additional Structures: Epiglottis, Hyoid Bone, Genioglossus Muscle, and Median Fibrous Septum.

    • Intrinsic and Extrinsic tongue muscles

    • hypoglossal nerve innervates them