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Tongue
Divides into left and right halves
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Intrinsic Muscles of Tongue
- Superior Longitudinal Muscles
- Inferior Longitudinal Muscles
- Vertical Muscles
- Transverse Muscles
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Extrinsic Muscles
- Genioglossus
- Hyoglossus
- Palatoglossus
- Styloglossus
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Superior Longitudinal Muscles
- Create upper layer of tongue
- Shorten and pull tongue tip up when contracted
- Curl Tongue tip and sides
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Inferior Longitudinal Muscles
- Run along lower sides of the tongue
- Shorten and pull tongue tip down
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Vertical Muscles
- In the sides of the tongue
- Flatten tongue when contracted
- At right angles to the transverse muscles
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Transverse Muscles
- Extend from center to the sides of the tongue
- Narrow and elongate the tongue when contracted
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Genioglossus
- Largest of 4 extrinsic muscles
- Bundles of muscle fibers
- Originates from in side middle of lower jaw
- Inserts into the center of the tongue
- Extends from the tip of tongue to the hyoid bone
- Aids in the retraction and protrusion of the tongue
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Hyoglossus
- Originates from hyoid bone
- Inserts into sides and back of tongue
- Runs along side the genioglossus
- Pulls sides of the back of the tongue down when contracted
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Palatoglossus (Anterior Faucial Pillar)
- Lowers velum
- Originates at soft palate
- Inserts into back of tongue
- Works in opposition to hyoglossus
- Pulls back sides of tongue up
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Styloglossus
- Works in opposition to genioglossus
- Draws tongue back and up when contracted
- Originates at styloid process of the temporal bone
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Mandible
- Main Purpose: Chewing
- Changes the shape and size of our vocal tract
- *Tongue can be moved independently of the mandible
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Corpus
- Body of the Mandible
- Contains Lower teeth
- Skeletal Framework for floor of the mouth
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Ramus
Vertical portion of mandible at right angles to the body
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Coronoid Process
Projection of the Ramus
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Condylar Process
- Projection of ramus
- Part of mandible that articulates with the skull
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Temporomandibular Joint (TMJ)
- Where skull and mandible articulate
- Allows jaw to move up, down, and from side to side
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Masseter Muscle
- Strongest of the mandibular muscles
- Originates at zygomatic arch (cheek bone)
- Inserts into angle and ramus of the mandible
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Medial Pterygoid Muscle
- On inside of mandible
- Originates at medial pterygoid plate of the sphenoid
- Inserts into angle and ramus of the mandible on the inside
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Temporalis Muscle
- Flat fan shaped muscle
- Originates at temple
- Goes under zygomatic arch and inserts into coronoid process
- Raises jaw quickly
- Doesn't have power for chewing
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Lateral Pterygoid Muscle
- Originates from greater wing of the sphenoid and lateral pterygoid plate
- Inserts into condyle just below the tempormandibular joint
- Extends horizontally back
- Assists in grinding, protrusion of jaw, and opening the mouth
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Mylohyoid; Geniohyoid; Anterior Belly of Digastric
- 3 small muscles that pull on corpus and lower the jaw
- Originate at lower corpus of the mandible
- Insert into hyoid bone
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Hyoid Bone
- Acts as a platform for larynx and trachea
- Platform for lowering the jaw
- Platform to which tongue is attached
- Tongue is protruded by pulling hyoid forward
- Horseshoe shaped
- Not attached to another bone
- Can be pulled forward, backward, up, and down
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Suprahyoid Muscles
Suspend the hyoid and pull it back and forth
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Mylohyoid; Geniohyoid; Anterior Belly of Digastric
Pull hyoid forward and slightly up which protrudes the tongue
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Stylohyoid; Posterior Belly of Digastric
- Suspend hyoid form the skull
- Originate at syloid process and mastoid process
- Pull hyoid back; retracts tongue
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Infrahyoid Muscles
- Pull hyoid down
- Located under hyoid
- 4 Muscles
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Thyrohyoid and Sternothyroid muscles
Descend from muscle and insert into larynx
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Omohyoid and Sternohyoid Muscles
Insert into hyoid
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Biological Functions of Articulators
- Mastication: ability to move unchewed food to the teeth to mix with saliva
- Deglutition: process of swallowing
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Dysphagia
impaired swallowing
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Swallowing
- Fetus swallows 10-11 weeks after conception
- 600-900 times per day for adult
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4 Stages of Swallowing
- Oral Preparatory Phase
- Oral Phase
- Pharyngeal Phase
- Esophageal Phase
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Oral Preparatory Phase
- Food is prepared for swallowing
- Voluntary process that can be performed automatically
- Introduce food to the mouth
- Grind food and mix it with saliva
- Move food back to center of the tongue
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Oral Phase
- Food is ready to be swallowed
- Food is formed into bolus (soft mass of food)
- Tongue propels back toward faucial pillars
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Pharyngeal Phase
- Contact with faucial pillars triggers it
- Velopharyngeal closure occurs
- Process of swallowing becomes reflexive
- Respiration is interrupted; VF close and epiglottis comes down
- Peristaltic wave carries bolus to esophagus
- Ends when food has reached the esophagus
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Esophageal Phase
- Bolus reaches opening of esophagus
- Breathing is resumed
- 10-20 secs for food to reach stomach
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