Muscles of Mastication Flashcards
What is an origin?
Attached to the least moveable structure
What is insertion?
Attached to the more moveable structure
What is action?
Movement accomplished by muscle contraction
How many muscles are involved in mastication?
4
What are the muscles involved in mastication?
Masseter, Temporalis, Medial Pterygoid, and Lateral Pterygoid
What nerve controls the muscles of mastication
V3
What does the nerve V3 used for in mastication?
Coordinat movement of teeth for mastication
What is mastication?
Where digestion starts
What is the process of mastication?
Ingestion of food and muscles coordinate to place food between opposing teeth
What is amylase?
An enzyme that starts digestion. (it breaks down the starches)
The muscle masseter is controlled by what nerve?
V3
What is the action of the masseter muscle?
Elevation of the mandible
How many parts are there to the masseter muscle?
2
What are the parts of the masseter muscle?
Superficial and Deep
The origin of the Superficial masseter is attached where?
Anterior 2/3; inferior zygoma
The origin of the deep masseter is attached where?
Posterior 1/3; medial of zygoma
The insterion of superficial masseter attaches where?
Lower 1/2 external surface of ramus, angle of mandible
The insertion of deep masseter attaches where?
Lower 1/2 of external ramus
Is the masseter a strong or weak muscle
Strong
The muscle Temporalis is controlled by what nerve?
V3
The origin of the temporalis is where
Temporal fossa
The insertion of the temporalis is where?
Coronoid process
**Where do the fibers of the temporalis pass?
Medial to the zygomatic arch
What is the action of the temporalis muscle?
Elevation of the mandible
What bones are included in the temporal fossa?
Temporal, Parietal, Frontal, Spheniod
Retrusion?
Like moving the mandible posterior
Is the temporalis a powerful muscle?
NO
The muscle Medial Pterygoid is controlled by what nerve?
V3
What is the origin of the medial pterygoid muscle?
Medial of the lateral pterygoid pate
Where is the insertion of the medial pterygoid muscle?
Medial of the mandibular angle
What is the action of the medial pterygoid muscle?
Elevation of the mandible
What muscle with the action of the masseter creates a supportive “sling” for the mandible?
Medial pterygoid muscle
What is the origin of the inferior Lateral Pterygoid muscle?
Lateral of the lateral pterygoid plate
How many portions of the Lateral pterygoid muscle are there
2
What are the portions of the Lateral pterygoid muscle?
Inferior and Superior
What muscle attaches to the greater wing of the Spheniod bone?
Lateral Pterygoid muscle
What nerve controls the Lateral Pterygoid muscle?
V3
What portion of the lateral pterygoid muscle is bigger?
Inferior
What is the origin of the superior Lateral pterygoid muscle
Greater wing of the spheniod
What is the insertion of the inferior lateral pterygoid muscle?
Anterior of Condyle neck
What is the insertion of the superior lateral pterygoid muscle?
Some fibers to TMJ capsule
What is the action of the lateral pterygoid muscle?
- slight depression of mandible
- protrusion of mandible
- “shifting” of the mandible
How many actions doe the lateral pterygoid muscle have?
3
What is a minor action of the lateral pterygoid muscle?
Slight depression of mandible
What action is the Lateral pterygoid muscle known for?
Protrusion of mandible
When you have a bilateral contraction of the Lateral pterygoid muscle what happens?
“PROTRUSION”
You will get protrusion of the mandible
When you have unilateral contraction of the lateral pterygoid muscle what happens?
“SHIFTING”
If you contract muscle on the right mandible moves left. If you contract muscle on the left mandible moves right
What is hypertrophy?
Enlarge the volume of the cells in the muscle tissue
When you enlarge the cells of muscle tissue what is it called?
Hypertrophy