Lecture 21 Flashcards
What are the 4 mandibular depressors?
1) anterior belly of digastric
2) mylohyoid
3) geniohyoid
4) lateral pterygoid
What does a mandibular depressor muscle do?
Lower the jaw
Of the anterior belly of digastric, mylohyoid, and geniohyoid, the __________ is the most superficial and _______, and the __________ is the deepest and most __________.
Anterior belly of digastric; inferior; geniohyoid; superior
The lateral pterygoid is also called the ________ __________
External pterygoid
What is the origin(s) of the lateral pterygoid?
2 heads:
1) superior head - lateral part of the greater wing of the sphenoid bone
2) inferior head - lateral surface of the lateral pterygoid plate
What is the insertion of the lateral pterygoid?
Condyle process
What is the function of the lateral pterygoid?
Depresses and protrudes the jaw
What are the 3 mandibular elevators?
1) masseter
2) temporalis
3) medial pterygoid
Which is the most superficial mandibular elevator?
Masseter
The masseter is the _______, most _______ muscle of ____________.
Largest; powerful; mastication
What are the 2 layers of the masseter?
1) external
2) internal
What is the origin of the masseter?
Zygomatic arch
What is the insertion of the masseter?
Angle of the mandible, ramus
What are the 2 functions of the masseter?
1) help to place maximum force on the molars - chewing
2) contraction elevates/closes the mandible
What muscle is deep to the masseter?
Temporalis muscle
The temporalis muscle is ____ and ___-shaped
Thin; fan shaped
What are the attachments of the temporalis?
Arises from the temporal and parietal bones and inserts at the Coronoid process and ramus
What is the function of the temporalis muscle?
Elevate and draw back the mandible
Is the temporalis more important for chewing or speech?
Chewing
What is another name for the medial pterygoid muscle?
Internal pterygoid
What are the attatchments of the medial pterygoid muscle?
1) medial surface of the lateral pterygoid plate
2) medial surface of the angel of the mandible
What is the function of the medial pterygoid?
jaw elevator for speech
Why isn’t the medial pterygoid a good muscle for mastication?
It’s unilateral contraction cant create rotary motion used for chewing and grinding
Which mandibular elevator is most important for speech?
Medial pterygoid muscle
The medial pterygoid is _______, and is ____ to the mandible and the masseter is _______ to it.
Internal; deep; lateral
What is the biological function of the tongue?
Swallowing: shaping the bolus, transporting the bolus to the pharyngeal cavity
What are the 5 important parts of the tongue?
1) tip
2) blade
3) dorsum
4) root
5) body
What are the two sets of tongue muscles?
1) intrinsic
2) extrinsic
What does it mean that the tongue is a “muscular hydrostat”?
Describes the tongue creating hydraulic function/movement without fluid
What are the 4 intrinsic tongue muscles?
1) superior longitudinal
2) inferior longitudinal
3) vertical/verticalis
4) transverse
What is the function of the intrinsic tongue muscles?
Tongue shaping
How does the superior longitudinal shape the tongue?
Pulls the tip up and elevates/shortens/retracts the tongue
How does the inferior longitudinal shape the tongue?
Shortens/retracts the tongue and tip is tiled downward
How does the vertical shape the tongue?
Flattens the tongue
How does the transverse shape the tongue?
Narrows and elongates the tongue
How does the superior longitudinal course?
Anterior to posterior
How does the inferior longitudinal course?
Posteriorly and inferiorly from tip
How does the vertical course?
Superior surface to inferior surface
How does the transverse course?
Radiating, courses laterally
Where is the superior longitudinal located?
Superior surface
Some of the inferior longitudnals fibers attach to the body of the ______, and is located between/blends with the ___________ and _________
Hyoid; genioglossus; hyoglossus
Where is the vertical muscle located?
Throughout the mass of the tongue body
What are the 4 extrinsic tongue muscles?
1) genioglossus
2) styloglossus
3) hyoglossus
4) palatoglossus
What are the attatchments of the genioglossus?
O: posterior surface of the mental symphysis
I: tongue tip and root of tongue
How do the anterior and the posterior fibers of the genioglossus run?
Anterior - course superiorly to tongue tip
Posterior - course inferiorly to body and root of tongue
What is the function of the genioglossus?
Protrude the tongue
What are the attachments of the styloglossus?
O: styloid process
I: sides of the tongue root
What is the function of the styloglossus?
Pull the tongue upward and backward
What two extrinsic tongue muscles are antagonistic?
Genioglossus and styloglossus
What are the attachments of the hyoglossus?
O: hyoid
I: side of tongue
What is the function of the hyoglossus?
Retracts and depresses tongue, may elevated hyoid bone
What are the attatchments of the palatoglossus?
O: anterior surface of velum
I: side of the tongue
What is the function of the palatoglossus?
Depresses soft palate and elevates back of tongue
Which extrinsic tongue muscle is important for “k” and “g” sounds?
Palatoglossus
Which extrinsic tongue muscle is important for low vowel sounds?
Hyoglossus
What are the 2 major ways the tongue movements influcence speech
1) tongue shaping
2) tongue positioning
Overal positioning and shaping of the tongue are important for _________ and ___________
Articulation; resonance
What is the name of the structure that extends from the lingual surface of the gum to inferior surface of the tongue?
Lingual frenulum
What is ankyloglossia?
Tongue tie
What are some (4) points of debate/issue about frenulectomies and their necessity?
1) feeding difficulties
2) speech difficulties
3) dentition
4) cosmetic
