Muscles of Facial Expression

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Questions and Answers

What is the primary action of the Orbicularis Oris muscle?

Closes and opens the mouth (correct)

Elevates the upper lip

Raises the corners of the mouth

Depresses the lower lip

Which muscle is responsible for elevating the upper lip?

Levator Labii Superioris (correct)

Depressor Labii Inferioris

Orbicularis Oris

Zygomaticus Major

Where does the Zygomaticus Minor muscle originate?

Lower rim of the orbit

Some bony attachment above the chin

Beneath the oblique line of the mandible

Zygomatic arch (correct)

Which nerve supplies the Depressor Labii Inferioris muscle?

Mandibular branch of the facial nerve Signup and view all the answers

What artery supplies blood to the Zygomaticus Major muscle?

Facial artery Signup and view all the answers

Which muscle is responsible for depressing the corner of the mouth?

Depressor Anguli Oris Signup and view all the answers

What is the primary blood supply for the Buccinator muscle?

Facial artery Signup and view all the answers

Which muscle originates from the canine fossa of the maxilla?

Levator Anguli Oris Signup and view all the answers

What is the nerve supply for the Platysma muscle?

Facial nerve, cervical branch Signup and view all the answers

Which action is performed by the Mentalis muscle?

Puckers the skin of the chin Signup and view all the answers

Where does the Risorius muscle insert?

Orbicularis Oris at the corners of the mouth Signup and view all the answers

Which muscle assists with mastication by directing food to the occlusal tooth surfaces?

Buccinator Signup and view all the answers

Which component of the Occipitofrontalis is associated with facial expression?

Frontalis Signup and view all the answers

Which statement accurately describes the function of facial muscles?

They allow for a range of facial expressions and assist in speech. Signup and view all the answers

What is true about the innervation of the facial muscles?

They are all innervated by the facial nerve. Signup and view all the answers

Which group of muscles includes those around the eyes and mouth?

Muscles of facial expression Signup and view all the answers

Which of the following correctly defines the insertion of facial muscles?

They predominantly insert into the skin. Signup and view all the answers

What is the primary blood supply to the facial muscles?

The facial artery. Signup and view all the answers

Study Notes

Muscles of Facial Expression

Muscles of facial expression originate from bone or fascia and insert into the skin
Facial muscles are innervated by the facial nerve and supplied by the facial artery
Facial nerve has five branches
Facial muscles help with speech, mastication and facial expressions

Mouth Muscles

Orbicularis Oris:
- Circles the oral cavity in lip tissue
  
  Origin: Some bony attachment (anterior nasal spine and midline above the chin)
  
  Insertion: Fibres interlace with muscles around the lips
- Closes and opens the mouth, compresses the lips, protrudes the lips
- Innervated by the facial nerve, buccal branch
- Supplied by the facial, maxillary, and superficial temporal arteries
- Latin origin:
  
  Orbis = circle or disk
  
  Oris = mouth or opening
Levator Labii Superioris:
```
       **Origin:** Lower rim of orbit

      **Insertion:** Fibres of Orbicularis Oris at the upper lip
```
- Elevates upper lip
- Innervated by the facial nerve, zygomatic and buccal branches
- Supplied by the facial & maxillary arteries
- Latin origin:
  
  Levator = to lift
  
  Labium = lip
  
  Super= above
  
  Oris = mouth
Depressor Labii Inferioris:
```
     **Origin:** Beneath the lowest portion of the oblique line of the mandible

      **Insertion:** Orbicularis Oris in the lower lip
```
- Depresses lower lip
- Innervated by the facial nerve, mandibular branch
- Supplied by the facial & maxillary arteries
- Latin origin:
  
  De = down
  
  Premere = to press
  
  Labium = lip
  
  Inferior = lower
Zygomaticus Minor:
```
  **Origin:** Zygomatic arch

    **Insertion:**  Orbicularis Oris
```
- Elevates upper lip
- Innervated by the facial nerve, buccal & zygomatic branches
- Supplied by the facial artery
- Zygomaticus- zygomatic bone

Zygomaticus Major:

      **Origin:** Zygomatic arch

       **Insertion:** Travels downwards and medially to blend with Orbicularis Oris at angle of mouth

Elevates corners of mouth
Innervated by the facial nerve, buccal & zygomatic branches
Supplied by the facial artery

Levator Anguli Oris:
```
     **Origin:**  Canine fossa of the Maxilla, below the  infra-orbital foramen

    **Insertion:** The Orbicularis Oris at corner of the mouth
```
- Elevates the corner of the mouth
- Innervated by the facial nerve, buccal & zygomatic branch
- Supplied by the facial & maxillary arteries
- Latin origin:
  
  Levator= to lift
  
  Angulus= corner
  
  Oris= mouth
Depressor Anguli Oris:
```
    **Origin:** Beneath angle of the mandible

   **Insertion:** Converges into the angles of the mouth and blend with Orbicularis Oris
```
- Depresses corner of the mouth
- Innervated by the facial nerve, buccal & mandibular branches
- Supplied by the facial & maxillary arteries
- Latin origin:
  
  De = down
  
  Premere = to press
  
  Angulus = corner
  
  Oris = mouth
Mentalis:
```
      **Origin:** Anterior surface of mandible (incisive fossa)

       **Insertion:** Skin covering the chin
```
- Puckers/pulls skin of the chin up, helps the Orbicularis Oris muscle in clearing food from the labial sulcus
- Innervated by the facial nerve, mandibular branch
- Supplied by the facial & maxillary arteries
- Referred to as the ‘pouty muscle’
  
  Latin origin:
  
  Mentum= the chin
Buccinator:
```
     **Origin:** Pterygomandibular raphae and buccal alveolar bone (in maxillary and mandibular molars regions)

     **Insertion:** Blend with the Orbicularis Oris at corners of mouth
```
- Pulls corner of the mouth back and compresses cheek against the buccal surfaces of molars, aids in mastication working in opposition with the tongue to direct food to the occlusal tooth surfaces
- Innervated by the facial nerve, buccal branch
- Supplied by the facial & maxillary arteries
  
  Also known as the ‘trumpeter muscle’
  
  Bucca latin for cheek- the cheek was used to blow into a horn so…
  
  The latin Buccina meaning trumpet, and buccinator means the trumpeter
Risorius:
```
    **Origin:** Angle of the mandible

     **Insertion:** Corner of the mouth
```
- Retracts the angle of the mouth, assists in smiling
- Innervated by the facial never, buccal branch
- Supplied by the facial artery
- Latin origin:
  
  Risus = laugh

Scalp Muscles

Occipitofrontalis:
- Consists of 3 parts: Frontalis, Occipitalis, Galea Aponeurotica
- Origin: Connective tissue of the scalp
- Insertion: Skin of the frontal regions of the eyebrows
- Pulls scalp up and back, elevates eyebrows and wrinkles scalp
- Innervated by the facial nerve, temporal branch
- Supplied by the Superficial temporal & opthalmic arteries
- Frons or fontis = brow or the fore part of something

Neck Muscle

Platysma:
- Origin: Clavicle & shoulder
  
  Insertion: Lower border of mandible, skin & muscle of lower face & mouth
  
  Action: Pulls down corners of mouth (grimace), and wrinkles skin of chin & neck
  
  Nerve Supply: Facial nerve, cervical branch
  
  Blood Supply: Facial artery & thyrocervical trunk
  
  Platysma = flat plate

Eye Muscles

Orbicularis Oculi:
- . Orbital: Horseshoe shape encircling the eye. Originates from the bone of the upper medial orbital margin Action:** Closes the eye forcefully
- Palpebrae: Originates from the medial palpebral ligament and arches laterally within the eyelid. Action:** Close eyes gently (blinking)
- Closes the eyelids, helps with blinking
- Innervated by the facial nerve, temporal and zygomatic branches
- Supplied by the facial, ophthalmic and infraorbital arteries
- Latin origin:
  
  Orbis= circle or disk
  
  Oculus = eye

Corrugator

Origin: Bridge of the nose
Insertion: Skin of the lateral part of eyebrow
Action: Pulls eyebrows medially (frown)
Nerve Supply : Facial nerve, temporal branch
Blood Supply :Superficial temporal artery
Latin origin:

Corrugare = to wrinkle
Procerus:
```
     **Origin:**  Bridge of the nose

     **Insertion:** Medial end of the eyebrows
```
- Pulls the skin of the forehead downwards, causes glabellar frown lines (between eyebrows), and wrinkling of the nose
- Innervated by the facial nerve, zygomatic branch
- Supplied by the facial artery
- Latin:
  
  Procerus = tall or extended

Other Facial Muscles

Nose:
- Nasalis:

The nasalis is made up of 2 parts that open and close the nostrils:

Dilator Naris:

  Origin: The nasal margin of the maxilla

   Insertion: Skin of the nostril

  Action: Flares the nostrils

Compressor Naris:

Origin: The top of the maxillary canine ridge

Insertion: Midline over the nasal cartilage

Action: Closes the nostrils

Nerve Supply: Facial nerve, buccal branches
Blood Supply: Facial artery
Ears:
- Anterior Auricular:
  - Origin:The scalp and temporal fascia
  - Insertion: Anterior medial aspect of the helix of the ear
  - Action: Pulls the ear slightly forward
  - Nerve Supply: Facial nerve, temporal branch
  - Blood Supply:Posterior auricular artery
  - Superior Auricular:
  - Origin: Scalp and temporal fascia
  - Insertion: Superior medial aspect of the ear
  - Action: Raises the ear
  - Nerve Supply: Facial nerve, temporal branch
  - Blood Supply: Posterior auricular artery
- Posterior Auricular:
  - Elevates the ear
  - Innervated by the facial nerve
  - Supplied by the superficial temporal artery