DNH 115 Chapter 30: Muscle of facial expression

The muscles of the ears, scalp, neck, eyes, nose, and mouth are all innervated by which nerve?

The seventh (VII) cranial nerve (facial)

All facial muscle are innervated by which never?

VII (7th) cranial nerve, facial nerve

What are the three pairs of ear muscles?

Anterior auricluar muscle, superior auricular muscle, posterior auricular muscle

The anterior auricular muscle arises from?

Tissue of the scalp in front of the ear

The anterior auricular muscle runs where?

Posteriorly into the anterior part of the ear

The anterior auricular muscle does what to the ear?

Pulls the ear slightly forward

The superior auricular muscle arises from where?

Connective tissue of the scalp above the ear

The superior auricular muscle fibers run where?

Down and insert into the upper part of the ear

The superior auricular muscle does what to the ear?

Raises the ear

The posterior auricular muscle arises from where?

The superior nuchal line of the occipital bone and mastoid area

The posterior auricular muscle fibers run where?

Forward to insert into the posterior part of the ear

What is the posterior auricular muscle does what to the ear?

Pulls the ear back

Occipitofrontalis (epicranius) allows what?

For either forward or backward movement of the scalp, resulting in either a squint or look of surprise

The occipitifrontalis (epicranius) is also known as the what?

scalp

The occipitofrontalis (epicranius) has how many bellies and what are they?

2 bellies: frontalis muscle & occipitalis muscle

The upper end of the platysma fibers attach where?

To the inferior border of the mandible (near angles of the mouth)

The platysma fibers pass where?

They pass down in broad flat sheet ending in skin of the chest just below clavicle

What is the function of the platysma?

Muscle moves skin over the neck, pulling corners of the mouth down or the skin of upper pectoral region up

What are the functions of the muscles located around the eyes?

They close the eyes and move eyebrows

The orbicularis Oculi has how many parts and what are they?

TWO PARTS! Orbital part & palpebral part

Which part of the orbicularis oculi encircles the eye & attaches to the skill at the medial and lateral edges of the orbit?

ORBITAL PART

Which part of the orbicularis oculi is associated with the eyelid & has fibers that attach at the medial and lateral corners of the orbit?

PALPEBRAL PART

What is the function of the orbicularis oculi?

Closes the eyelids & contracts the skin around the eye

What is the origin of the levator palpebrae superioris?

Origin is back of the orbit/tissue of upper eyelid

Where does the levator palpebrae superioris insert?

Inserts into the upper eyelid

What is the function of the levator palpebrae superioris?

Raises the upper eyelid

The levator palpebrae superioris is supplied by which nerve?

III cranial nerve (oculomotor nerve)

Why is the levator palpebrae superioris considered a muscle of the orbit?

Because it is NOT innervated by the facial never

The corrugator runs from where?

From the bridge of the nose up to the lateral part of the eyebrow

What is the function of the corrugator?

Pulls the eyebrow medially and down

Name the insertion of the corrugator

LATERAL aspect of the eyebrow

What is the function of the procerus?

Pulls the eyebrow at the medial end down

The procerus extends from where?

The bridge of the nose & fibers extend up medial side of the eyebrow

Muscles of the nose primarily circle what?

The opening of the nostrils

The nasalis is the muscle that what?

Opens and closes the nostrils

The nasalis is composed of how many parts and what are they?

TWO PARTS! Dilator naris & compressor naris

Name the function of the dilator naris

Pulls down on nostrils, causing them to flare or dilate

Name the function of the compressor naris

Causes nostrils to close or compress

Name the origin of the procerus

Nasal bones (bridge of nose)

Name the insertion of the procerus

Medial aspect of eyebrows

Name the origin of the Nasalis (dilator & compressor)

Maxilla bone

Name the insertion of the nasalis (dilator & compressor)

Midline where nasal bones meet

The orbicularis oris circles what?

The oral cavity within the tissue of the lip

What is the function of the orbicularis oris?

Closes and compresses the lips

What is the function of the levator labii superioris?

Elevates the upper lip

What is the origin of the levator labii superioris?

Just beneath the lower rim of the orbit

In the levator labii superioris the fibers run how?

The fibers run down and insert midway between center of the upper lip & corner of mouth into fibers of orbicularis oris

What is the function of the zygomaticus minor?

Raises the upper lip

What is the zygomaticus minor?

Small muscle from the area of zygomatic bone

How do the fibers run of the zygomaticus minor?

Fibers run down and forward

Where does the zygomaticus minor insert?

Inserts into orbicularis oris just lateral to the levator labii superioris

Where does the zygomaticus MAJOR originate from?

From zygomatic bone

How does the zygomaticus MAJOR run?

Runs lateral to zygomaticus minor on most prominent portion of the cheek. Runs down and forward to insert into orbicularis oris at the angle of the mouth

Where does the zygomaticus MAJOR inset?

Into the orbicularis oris at the angle of the mouth

What is the function of the zygomaticus MAJOR?

Elevates the corners of the mouth to make a smile!

Levator Anguli Oris lies where?

DEEP to the levator labii superioris, zygomaticus major and zygomaticus minor

Where does the levator anguli oris originate from?

From the maxilla, just below infraorbital foramen

How do the fibers run in the levator anguli oris?

They run down and laterally into the orbicularis oris at the corners of the mouth

What is the function of the levator anguli oris?

Pulls the angles of the mouth up and toward the midline

Where is the origin of the Depressor Labii Inferioris?

Is area beneath the angles of the mouth and just above the inferior border of the mandible

How do the fibers run in the Depressor Labii Inferioris?

They run up and medially to inert into the fibers of the orbicularis oris toward the middle of the lower lip

What is the function of the Depressor Labii Inferioris?

Pulls the lower lip down

What is the origin of the Depressor Anguli Oris?

Same general area as depressor labii inferioris (area beneath the angles of the mouth and just above the inferior border of the mandible)

How do the fibers run in Depressor Anguli Oris?

They run up and converge in a triangular shape to blend into the orbicularis oris at the angle of the mouth

What is the function of the Depressor Anguli Oris?

Pulls the corner of the mouth down

Where is the origin of the Mentalis?

Originates on the anterior surface of the mandible just beneath the lateral incisors

How do the fibers run in the Mentalis?

Run down and toward the midline. SOME fibers cross to meet the muscle on the opposite side, terminating with insertion into the skin of the chin

What is the function of the Mentalis

Pulls the skin on chin up

What is probably the most important muscle of the mouth>

Buccinator

What is so important about the buccinator muscle?

Muscle of facial expression BUT also plays a role in mastication!

What is the buccinator sometimes called?

Accessory muscle to mastication

What is the origin of the buccinator?

From the pterygomandibular raphe & buccal alveolar bone of the maxillary and mandibular molars

How do the fibers run in the buccinator?

Run anteriorly making up musculature of the cheek

Where do the fibers insert in the buccinator?

Into the orbicularis oris at the corners of the mouth

How does the Pterygomandibular Raphe extend?

Inferiorly from the pterygoid hamulus into the retromolar region

When the mouth is open widely, how is the Pterygomandibular Raphe positioned?

It is stretched causing it to look like string between the pterygoid hamulus and retromolar pad

What happens when the buccinator contracts?

It pulls the corners of the mouth back and compresses the cheek

What is the Risorius muscle?

Small muscle that arises from the soft tissue near the angle of the mandible near parotid gland

What is the origin of the Risorius muscle?

Arises from fascia over the parotid gland (near angle of mandible)

What is the insertion of the Risorius muscle?

Corner of the mouth; very weak muscle

What is the function of the Risorius muscle?

Poorly developed, may help in smiling