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Supralaryngeal Anatomy

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Muscles of Face

• Facial muscles are devoid of facial sheaths (characteristic of skeletal muscle)

• Size, shape & extent of development depend on– age

– dentition

– sex

• Lips are most mobile

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Facial Muscles

Risorius

LevatorLabii

Superioris

DepressorAnguliOrisMentalis

OrbicularisOris

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Orbicularis Oris• Principal muscle acting on the lips• Oval ring of muscle encircling mouth• Paired: upper & lower muscles (superior

& inferior), functional differentiation• Acts as point of insertion for many other

muscles• Function: Protrude & close lips,

compress, contract, extend, rounding

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Obicularis Oris

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Buccinator

• “Bugler’s muscle”

• Lies deep to the risorius

• Originates on the pterygomandibular ligament

• Inserts into the lower orbicularis oris

• Function: Compresses the lips & cheeks against the teeth & draws the corners of mouth laterally; primarily involved in mastication, moves food onto grinding surface of the molars, contraction constricts the oropharynx

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BuccinatorPterygomandibular

Ligament

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Levator Anguli Oris

• Arises from the canine fossa of the

maxilla (lower part of orbit)

• Inserts into upper & lower lips

• Function: Draws the corner of the mouth

up and medial-ward (spreads lips)

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Levator Anguli Oris

Canine Fossaof Maxilla

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Levator Labii Superioris

• Originates from the infraorbital margin

of the maxilla (lower part of orbit)

• Insertion into the mid-lateral region of

the upper lip

• Function: Elevation of the upper lip

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Levator Labii Superioris Infraorbital margin

of Maxilla

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Zygomatic Major

• Arises on the zygomatic bone

• Courses obliquely

• Inserts into the corner of the obicularis oris

• Function: Elevates and retracts the angle of the mouth, as in the gesture of smiling

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Depressor Labii Inferioris

• Originates oblique line of mandible, runs upward

• Insert into the lower lip and orbicularis oris

• Function: Depresses the corners of the mouth and, by virtue of attachment to lower lip, help compress the lower lip to the upper lip

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Depressor Labii Inferioris

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Mentalis

• Origin from incisive fossa of mandible, inserting into skin of chin below (lower gum in area of mandibular teeth)

• Function: contraction elevates and wrinkles the chin and pulls the lower lip out

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Masseter

• Originates for zygomatic arch

• Insert into angle & lateral surface of the

ramus of the mandible

• Function: Closes jaw & retracts the

mandible

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Masseter

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Facial Muscles• Obicularis oris, inferior & superior muscles:

– Lip protrusion, closure, retraction, elevation & depression

• Risorius & Buccinator:– Assist in retraction of the lips & support entrapment of air

within the oral cavity

• Levator labii superioris, zygomatic minor:– Elevate upper lip

• Depressor labii inferioris:– Depresses lower lip

• Zygomatic major:– Elevates & contracts corners of mouth

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Muscles of the Mouth

• Extrinsic & intrinsic muscles of the

tongue

• Muscles for soft palate elevation

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Tongue

• Occupies the floor of the mouth

• Extrinsic muscles: moves tongue into different positions or regions in the mouth

• Intrinsic muscles: Shapes tongue into contours; fine graded control of the articulatory gestures

• Primarily involved in mastication & deglutition– Movement of food– Position food for chewing– Propel it backward for swallowing

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Tongue• Dorsum: Superior surface

• Tip or Apex: Anterior-most portion

• Base: In oropharynx

• Palatine surface: Portion of surface in oral cavity; 2/3 of tongue

• Lingual Frenulum: Underside of tongue; Joins inferior tongue & mandible; stabilizing tongue during movement

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Intrinsic Tongue Muscles

• Two pairs of muscles running

longitudinally, transversely & vertically

• Interact in a delicate fashion to produce

the rapid, delicate articulations for

speech & nonspeech activities

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Intrinsic Tongue Muscles

• Superior Longitudinal:– Courses along the length of tongue

– Upper layer of tongue

– Originates from fibrous submucous layer near epiglottis

– Fibers fan forward & outward to insert into the lateral margins of the tongue & apex region

– Function: Elevate tongue tip, pulls tongue to one side (toward side of contraction)

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Superior & Inferior Longitudinal Muscles

Superior

Inferior

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Intrinsic Tongue Muscles

• Inferior Longitudinal Muscle:– Originates at the root of the tongue & corpus

hyoid

– Fibers course to apex of tongue

– Occupies lower sides of tongue (absent in medial tongue base)

– Function: Depresses tongue tip; assist in retraction of the tongue; Contraction to one side pulls tongue in that direction & downward

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Intrinsic Tongue Muscles

• Transverse Muscles:

–Function: to narrow tongue; Pulls

edges toward midline

–Fibers originate at the median fibrous

septum & course laterally to insert into

side of the tongue

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Transverse & Vertical Muscles

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Intrinsic Tongue Muscles

• Vertical Muscles:

– Run at right angles to the transverse

muscles

– Course from base of tongue and insert into

the membranous cover

– Function: Flatten tongue; Pulls tongue

down into the floor of the mouth

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Intrinsic Tongue Muscles

Vertical Muscles

Inferior LongitudinalTransverse

Muscles

Coronal

Superior Longitudinal

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Extrinsic Muscles

• Genioglossus:– Prime mover, most of deeper bulk

– Arises from inner mandibular surface and fans to insert into the tip & dorsum of the tongue

– Medial position

– Function: • 1. Withdraw tongue into mouth

• 2. Pull tongue tip down, lower the tongue

• 3. Protrude the tongue

• 4. Pull tongue root & dorsum anteriorly

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Genioglossus

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Extrinsic Muscles

• Hyoglossus:

– Arises from greater cornu & lateral body of the hyoid

– Inserts into the sides of the tongue between the styloglossus & inferior longitudinal

– Function: Pulls sides of tongue down

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Hyoglossus

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Extrinsic Muscles

• Styloglossus:

– Originates from antero-lateral margin of

styloid process

– Inserts into inferior sides of tongue;

divides to insert into inferior longitudinal

& hyoglossus

– Function: Draws tongue back & up

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Styloglossus

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Extrinsic Muscles

• Palatoglossus:

– Muscle of the tongue & velum

– Function: Depress the soft palate or

elevating the back of the tongue

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Palatoglossus

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Velopharyngeal Anatomy

• Soft palate & its relationship with the pharyngeal wall

• Muscles here run from skull and insert somewhere in palate

• Muscles important for speech-Cleft palate

• Three sounds in English that require velum to be depressed- n, m, ing

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Reading/Assignments

• Seikel: Pgs. 305-319

• Dickson: Pgs. 222-250