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Speech Therapy
Muscles of Facial Expression
| Question | Answer |
|---|---|
| Orbicularis Oris: Description? | Primary lip muscle Completely encircles oral opening No long fibers running around;short fibers overlap Composed of fibers exclusive to lips plus fibers from other facial muscles |
| Orbicularis Oris: Function? | When activated alone, closes mouth and puckers the lips; when activated with other muscles, closes mouth in a straight line |
| Buccinator: Description? | Principle muscle of the cheek; Deepest facial muscle |
| Buccinator: Origin? | Origin: Pterygomandibular ligament |
| Buccinator: Course? | Horizontal and anteriorly |
| Buccinator: Insertion? | Fibers decussate (cross) at the corners of the mouth to insert into orbicularis oris |
| Buccinator: Function? | Draws corners of mouth laterally |
| Risorius: Origin? | Fascia covering masseter |
| Risorius: Course? | Horizontally anterior; parallel and superior to buccinator |
| Risorius: Insertion? | Skin and mucosa at corners of the mouth |
| Risorius: Function? | Assists in drawing corners of mouth laterally |
| Transverse Muscles of Facial Expression? | Buccinator and Risorius |
| Angular Muscles of Facial Expression? | Zygomatic Major, Levator Labii Superior, and Depressor Labii Inferior |
| Zygomatic Major: Origin? | Surface of zygomatic bone |
| Zygomatic Major: Course? | Inferior and medial |
| Zygomatic Major: Insertion? | Orbicularis oris and skin at corner of mouth |
| Zygomatic Major: Function? | Draws corners of mouth superiorly and laterally (for broad smile) |
| Levator Labii Superior: Origin/Course? | Origin: Lower margin of orbit/inferiorly |
| Levator Labii Superior: Insertion? | Upper lip lateral to levator anguli oris |
| Levator Labii Superior: Function? | proper elevator for upper lip |
| Depressor Labii Inferior: Origin/Course? | Mandible; just lateral to midline/superiorly and medially |
| Depressor Labii Inferior: Insertion: | Insertion: Lower lip |
| Depressor Labii Inferior: Function? | Draws lower lip down and lateral |
| Vertical Muscles of Facial Expression? | Levator Anguli Oris, Depressor Anguli Oris, and Mentalis |
| Levator Anguli Oris: Origin? | Origin: Lateral to nasal ala (side of nare) |
| Levator Anguli Oris: Course/Insertion? | Course: Inferior/Insertion: Orbicularis oris with some fibers crossing to lower lip |
| Levator Anguli Oris: Function? | Draws corners of mouth superiorly and aids in closing lower lip |
| Depressor Anguli Oris: Origin/Course? | Origin: Mandible; just lateral to midline/Course: superior |
| Depressor Anguli Oris: Insertion? | Insertion: orbicularis oris with some fibers crossing to upper lip |
| Depressor Anguli Oris: Function? | Depresses angle of lip and draws upper lip down |
| Mentalis: Origin/course? | Origin: Mental tuberosity of the mandible/Course: superiorly |
| Mentalis: Insertion? | Some fibers insert into chin and some into orbicularis oris |
| Mentalis: Function? | Everts lower lip, wrinkles chin, stiffens lower lip so mouth can be closed in a straight line |
| What action is Depressor Anguli Oris responsible for? | This muscle is responsible for frowning. |
| What action is Menatlis responsible for? | This muscle is responsible for pouting. |
| As a group, what action are the Vertical Muscles responsible for? | This group of muscles is responsible for smiling and frowning. |
| As a group, what action are the Transverse Muscles responsible for? | This group of muscles is responsible for pulling the lips laterally. |