DH 228- Muscles of head and neck

What are the muscles of mastication responsible for?

Closing the jaws, bringing the lower jaw forward or backward, shifting the lower jaw to one side, working with the TMJ to accomplish these movements

origin

end of the muscle that is attached to the least movable structure

What are the 4 pairs of "chewing" muscles attached to the mandible?

masseter, temporalis, medial pterygoid, lateral pterygoid

insertion

opposite end of origin, that is attached to the more movable structure

action

work that is accomplished when the muscle fibers contract

Describe the hyoid muscles

2 groups of muscles: suprahyoid & infrahyoid- based on the muscle's vertical position in relationship to the hyoid bone (horseshoe-shaped bone suspended inferior to mandible, no bony articulations, just muscular and ligament are attachments). Both are attached in someway to the hyoid bone, both assist in the actions of mastication and swallowing.

Describe the buccinator muscle

A thin, quadrilateral muscle that forms the anterior portion of the cheek (cheek muscle), also makes up the lateral wall within the buccal region, important muscle, plays role in facial expression AND mastication (aids muscles of mastication by keeping food pushed back on occlusal surfaces of posterior teeth for chewing)

Describe the muscles of facial expression

All 15 originate from bone and insert in fascia (skin tissue), most are paired, contract in various combinations to vary the appearance of the face during facial expression (similar to the muscles of mastication)

What is the innervation for the muscles of facial expression?

All muscles are innervated by facial nerve (VII) (various branches of the motor division). Consider clinically- paralysis related to damage to facial nerve (results in inability to form facial expressions), occurs unilaterally unless both sides have been damaged, can result from stroke, Bell Palsy, parotid gland cancer

Which nerve innervates the muscles of mastication?

All muscles of mastication are innervated by: mandibular division of the trigeminal nerve (CN V3- motor portion), leaves skull via foramen ovale

C. Middle ear function

All the muscles of the pharynx are known to be involved in A. Closing the jaws B. Facial expression C. Middle ear function D. Stabilization of the mandible

What is the innervation of the digastric muscle?

Anterior belly: Mylohyoid nerve (branch of mandibular division of trigeminal nerve, CN V). Posterior belly: Facial nerve, CN VII, posterior digastric nerve branch)

Describe the temporalis muscles

Broad, fan-shaped muscle on each side of the head, fills the temporal fossa (made up from parts of the temporal, sphenoid, frontal and parietal bones)

What are the frown muscles?

Depressor anguli oris & corrugator supercilii

What are the pouting muscles?

Depressor labii inferioris & orbicularis oris

What are the 4 suprahyoid muscles?

Digastric, stylohyoid, mylohyoid & geniohyoid. These cause elevation of the hyoid bone and larynx, occurs during swallowing. Some also depress the mandible, form the floor of oral cavity and elevate the tongue

What is the blood supply for muscles of facial expression?

Facial artery- branch of the external carotid artery (ECA)

How would you palpate the masseter?

Have the patient clench their teeth, visually inspect and bilaterally palpate both muscles, placing fingers over muscle as patient clenches and relaxes several times, it can become enlarged in patients who habitually clench/grind their teeth

Which mastication muscle opens the jaw?

Lateral Pterygoid

Describe the medial pterygoid muscle (internal pterygoid)

Lies deep to the superficial masseter muscle, similar to masseter in rectangular form, 2 heads; deep & superficial

Which 3 muscles of mastication close the jaw?

Masseter, Temporalis, Medial Pterygoid muscles

Which muscle groups take part in the elevation of the mandible?

Masseter, temporalis, medial pterygoid muscles (closing the mouth)

What is the blood supply to the muscles of mastication?

Maxillary artery- branch of the external carotid artery (ECA)

Describe the masseter muscle

Most superficially located mastication muscle, one of the strongest, broad, thick, flat rectangular muscle on each side of the face, anterior to parotid salivary glands, 2 heads- superficial & deep

What is the innervation of the 4 suprahyoid muscles?

Mylohyoid nerve: branch of the mandibular division of the trigeminal nerve- anterior belly of digastric & mylohyoid muscle. Facial nerve: posterior belly of digastric & stylohyoid muscle. Hypoglossal nerve: geniohyoid muscle

Describe the epicranial muscle

One muscle of facial expression in the scalp region, this muscle and it's tendon are one of the layers that from the scalp. It has 2 bellies: frontal & occipital- separated but the epicranial aponeurosis (a large spread-out scalpal tendon)

Describe the muscles of facial expression in the orbital region

Orbicularis oculi- encircles the eye. Corrugator supercilii- deeper than superior border of the orbicularis oculi

List all muscles of facial expression in the oral region

Orbicularis oris, buccinator, risorius, levator labii superioris, levator labii superioris alaeque nasi, zygomaticus major, zygomaticus minor, levator aguli oris, depressor anguli oris, depressor labii inferioris, mentalis, platysma

Describe the lateral pterygoid muscle (external pterygoid muscle)

Short, thick, almost conical-shaped muscle, lies superior to medial pterygoid muscle, lies entirely within the infratemporal fossa, deep to the temporalis muscle, has 2 separate heads of origin separated by a space anteriorly but fuse posteriorly- superior head & inferior head

C. The muscle end attached to the least movable structure

The origin of a muscle is considered to be A. The starting point of a muscle B. Where the muscle fibers join the bone tendon C. The muscle end attached to the least movable structure D. The muscle end attached to the most movable structure

C. Epicranial aponeurosis

The origin of the frontal belly of the epic racial muscle and the insertion of its occipital belly are BOTH at the: A. Clavicle and sternum B. Mastoid process C. Epicranial aponeurosis D. Pterygomandibular raphe

B. Posterior suprahyoid muscle

The posterior belly of the digastric muscle is also considered a(n) A. Muscle of facial expression B. Posterior suprahyoid muscle C. Intrinsic muscle of the tongue D. Extrinsic muscle of the tongue

B. Insert on the median pharyngeal raphe

The superior pharyngeal constrictor muscle is noted to: A. Originate from the larynx B. Insert on the median pharyngeal raphe C. Overlap the stylopharyngeus muscle D. Be a longitudinal muscle of the pharynx

What are the smile muscles?

Zygomaticus major, zygomaticus minor, levator anguli oris, risorius

Alveolar process of maxilla, alveolar process of mandible, & pterygomandibular raphe (tendenous band that extends from the mauls and attaches to the posterior end of the mandible's mylohyoid line (internal oblique); intraoral lay noted as the mterygomandibular fold; spans the area between the retromolar pad area of the mandible and the junction of the hard and soft palates- important landmark for administration of local anesthesia

What are the areas of origin for the buccinator muscle?

Action: depresses mandible (aids in lateral pterygoid muscles in opening the jaws), and elevates hyoid bone to steady it during speech and swallowing

What is the action of the digastric muscle?

Raises eyebrows and scalp, (backward movement) as when a person shows surprise. Also can effect a forward movement to cause a frown or squint or wrinkling of the forehead skin horizontal

What is the action of the epicranial muscle?

Protrusion of the mandible, pulls mandible forward by pulling the condyle (forward sliding motion), occurs during opening of the jaws, occurs with bilateral contraction of both muscles. depression of the mandible; assists in lowering the mandible as it protrudes it forward during opening of the jaws. the only muscle of mastication that assist in opening the mouth. Side-to-side, lateral deviation of the mandible, shifts it contra lateral with unilateral contraction, creates grinding movements of the lower teeth when only one side contracts

What is the action of the lateral pterygoid muscle?

Elevates the mandible, with bilateral contraction of the entire muscle. =closing of jaw

What is the action of the masseter muscle?

Elevates the mandible during closure of jaw, accomplished by bilateral contraction, parallels action of the masseter muscle (but weaker)

What is the action of the medial pterygoid muscle?

Elevates & retracts mandible. Elevation if the entire muscle contracts. Retraction if the only the posterior portion contracts the muscles move the jaw backwards (retrusion or retraction). Also maintains the position of the mandible at rest

What is the action of the temporalis muscles?

Maxillary artery

What is the blood supply to the muscles of mastication?

Insertion: skin tissue and orbicularis oris at the labial commissures (muscle fibers interweave). Action: pulls labial commissures laterally (pulls corner of mouth back) and compresses cheek (whistling, blowing or sucking). Contraction keeps food in place for chewing (defined in nursing infants, known as Trumpeter's muscle due to importance in expelling air through wind instruments)

What is the insertion and action of the buccinator muscle?

Coronoid process via a tendon that passes beneath the zygomatic arch

What is the insertion for the temporalis muscle?

On the ramus above the angle of the mandible

What is the insertion of the deep head of the masseter?

Anterior surface of the neck of the mandibular condyle at the pterygoid fovea, some fibers insert at the anterior margin of the TMJ disc and capsule (entire TMJ joint is surrounded by a thick fibrous tissue called the capsule)

What is the insertion of the lateral pterygoid muscle?

Medial surface of the mandible (near the angle); this is opposite of the insertion of the masseter muscle, on the lateral side of the mandible.

What is the insertion of the medial pterygoid?

On the lateral surface of the angle of the mandible

What is the insertion of the superficial head of the masseter?

Origin: intermediate tendon loosely bound to the hyoid bone. Insertion: digastric fossa on medial surface of mandible, near symphysis.

What is the origin and insertion of the anterior belly of the digastric muscle?

Origin: mastoid notch of temporal bone. Insertion: intermediate tendon

What is the origin and insertion of the posterior belly of the digastric muscle?

From within pterygoid fossa on medial surface of lateral pterygoid plate of the sphenoid bone. (Larger head)

What is the origin of the deep head of the medial pterygoid muscle?

Lateral surface of the lateral pterygoid plate of the sphenoid bone

What is the origin of the inferior head of the lateral pterygoid?

Zygomatic arch- superficial head; originates from the anterior 2/3 of the lower border. Deep head; originates from the posterior third and the entire medial surface

What is the origin of the masseter muscle?

Lateral surfaces of palatine bones and maxillary tuberosity of maxillae

What is the origin of the superficial head of the medial pterygoid muscle?

Inferior surface of the greater wing of the sphenoid bone (roof of infratemporal fossa)

What is the origin of the superior head of the lateral pterygoid?

Wide origin from the entire temporal fossa, bound at the top by the inferior temporal line, and at the bottom by the infratemporal crest of the sphenoid bone

What is the origin of the temporalis?

Origin: Epicranila aponeurosis (scalpal tendon). Insertion: skin of the eyebrow & root of the nose. Action: raises eyebrows, wrinkles forehead (look of surprise)

What is the origin, insertion & action of the frontalis muscle (frontal belly of the epicranial muscle)

Origin: superior nuchal line (occipital bone), and mastoid process (temporal bone). Insertion: epicranial aponeurosis. Action: tenses and retracts scalp (raises eyebrows, wrinkles forehead- look of surprise)

What is the origin, insertion & action of the occipitalis muscle (occipital belly of the epicranial muscle)

Origin: frontal bone in supraorbital region. Insertion: skin tissue of eyebrow; passes laterally to attach to the skin tissue of eyebrow. Action: frowning, draws skin of eyebrow medially and inferiorly, causing vertical wrinkles

What is the origin, insertion and action of the corrugator supercilii?

Origin: lower border of mandible. Insertion: passes superiorly to insert on the skin tissue at the labial commissure. Action: depresses angle of mouth was when a person frowns

What is the origin, insertion and action of the depressor anguli oris?

Origin: lower border of mandible. Insertion: passes superiorly to insert into skin tissue of lower lip. Action: depresses lower lip, exposing lower incisor teeth- pouting

What is the origin, insertion and action of the depressor labii inferioris?

Origin: canine fossa of maxillae, superior to root of maxillary canine. Insertion: passes inferiorly to insert in skin tissue at labial commissures. Action: elevates angle of mouth, like in smile

What is the origin, insertion and action of the levator anguli oris muscle?

Origin: frontal process of maxillae. Insertion: passes inferiorly to insert in 2 areas: skin tissue of ala of nose & upper lip. Action: elevate upper lip and ala of nose, dilating nostrils as in a sneering expression

What is the origin, insertion and action of the levator labii superioris alaeque nasi?

Origin: infraorbital rim of maxillae. Insertion: passes inferiorly to insert into the skin tissue of upper lip. Action: raises upper lip

What is the origin, insertion and action of the levator labii superioris?

Origin: anterior surface of mandibular (just beneath lateral incisors, midline area). Insertion: skin tissue of chin. Action: raises chin, causing displaced lower lip to protrude and chin to wrinkle

What is the origin, insertion and action of the mentalis muscle?

Origin: nasal process of frontal bone and frontal process of maxillae; ligaments around orbital rim. Insertion: tissue of eyelid at lateral region of eye, some encircle the eye. Action: closes the eyelid, squinting, if all fibers are active eye squints and wrinkles form at lateral border (causing crow's feet)

What is the origin, insertion and action of the orbicularis oculi?

Origin: maxilla and mandible via fibers of other facial muscles, encircles mouth. Insertion: skin and muscles around borders and angle of mouth, in upper lip fibers also insert into philtrum. Action: closes lips, purses lips (tightening and thinning; sign of displeasure), rolling inward (grimacing), thrust outward (kissing, pouting)

What is the origin, insertion and action of the orbicularis oris?

Origin: skin superficial to the clavicle and shoulder. Insertion: inferior border of mandible and muscles surrounding mouth. Action: raises skin of neck and pulls corners of mouth down, as when a person grimaces, some sources indicate it aids in depression of the mandible. (Single muscle, runs from neck to mouth, thin sheet-like superficial neck muscle)

What is the origin, insertion and action of the platysma muscle?

Origin: soft tissue near angle of mandible, superficial to masseter muscle. Insertion: labial commissures. Action: widens mouth, as in a "wide smile", stretches lip

What is the origin, insertion and action of the risorius muscle?

Origin: zygomatic bone. Insertion: labial commissures (passes inferiorly and anteriorly to insert in the skin at angle of mouth). Action: elevates angle (corner) of mouth and pulls laterally as in a smile

What is the origin, insertion and action of the zygomaticus major?

Origin: body of zygomatic bone. Insertion: skin tissue of upper lip (adjacent to insertion of major). Action: elevates upper lip to assist in smiling

What is the origin, insertion and action of the zygomaticus minor muscle?

Origin: genial tubercles (mental spine). Insertion: hyoid bone. Action: depresses mandible (opens mouth), elevates hyoid bone, widens pharynx (for receiving food for swallowing). Innervation: hypoglossal nerve (CN XII)

What is the origin, insertion, action and innervation of the geniohyoid muscle?

Origin: mylohyoid line on the inner surfaces of the mandible (INTERNAL OBLIQUE LINE). Insertion: hyoid bone. Action: elevates hyoid bone, depresses mandible (opens mouth), forms floor of mouth, helps to elevate the tongue. Innervation: mandibular division of trigeminal nerve (mylohyoid nerve branch)

What is the origin, insertion, action and innervation of the mylohyoid muscle?

Origin: styloid process of temporal bone. Insertion: hyoid bone. Action: elevates hyoid bone and larynx during swallowing. Innervation: Facial nerve (CN VII)- stylohyoid nerve branch

What is the origin, insertion, action and innervation of the stylohyoid muscle?

Mandibular nerve (V3)

What nerve innervates the muscles of mastication?

A. Mentalis

Which muscle can make the patient's oral vestibule shallower, thereby making dental work sometimes difficult? A. Mentalis B. Zygomaticus major C. Depressor anguli oris D. Levator anguli oris

D. Epicranial muscle

Which muscle does NOT aid in smiling with the lips when it contracts? A. Zygomatic major muscle B. Levator anguli oris muscle C. Zygomaticus minor muscle D. Epicranial muscle

A. Platysma

Which muscle is located just deep to the skin of the neck? A. Platysma B. Buccinator C. Risorius D. Mentalis

A. Masseter muscle

Which muscle listed below is MOST superficial in regard to location? A. Masseter muscle B. Medial pterygoid muscle C. Lateral pterygoid muscle D. Superior pharyngeal constrictor muscle

C. Depressor anguli oris muscle

Which muscle listed below when contracted causes a frown? A. Zygomaticus minor muscle B. Levator anguli oris muscle C. Depressor anguli oris muscle D. Risorius muscle

A. Corrugator supercilii muscle

Which muscle listed is considered most SUPERIORLY located on the head and neck? A. Corrugator supercilii muscle B. Zygomatic major muscle C. Superior pharyngeal constrictor muscle D. Superior belly of the omohyoid muscle

B. Buccinator

Which muscle of facial expression compresses the cheeks during chewing assisting the muscles of mastication? A. Risorius B. Buccinator C. Mentalis D. Orbicularis oris E. Masseter

A. Genioglossus muscle

Which muscle's activity helps to prevent the tongue from sinking back and obstruction respiration? A. Genioglossus muscle B. Stylopharyngeus muscle C. Inferior longitudinal muscle D. Palatoglossus muscle

B. Originates from the zygomatic arch

Which of the following descriptions concerning the masseter muscle is CORRECT? A. Most superficial muscle of facial expression B. Originates from the zygomatic arch C. Inserts on the medial surface of the mandible's angle D. Depresses the mandible during jaw movement

E. Orbicularis oris

Which of the following is the MOST commonly used muscle when the patient's lips close around the saliva ejector? A. Risorius B. Mentalis C. Mylohyoid D. Buccinator E. Orbicularis oris

A. Geniohyoid, stylohyoid, and omohyoid muscles

Which of the following muscle groups inserts DIRECTLY on the hyoid bone? A. Geniohyoid, stylohyoid, and omohyoid muscles B. Masseter, stylohyoid, and digastric muscles C. Masseter, buccinator, and omohyoid muscles D. Palatopharyngeus and palatoglossus muscles and muscle of the uvula

C. Muscles of facial expression

Which of the following muscle groups is innervated by the facial nerve? A. Intrinsic tongue muscles B. Extrinsic tongue muscles C. Muscles of facial expression D. Muscles of mastication

B. Suprahyoid muscles

Which of the following muscle groups is involved in BOTH elevating the hyoid bone and depressing the mandible? A. Muscles of mastication B. Suprahyoid muscles C. Infrahyoid muscles D. Intrinsic tongue muscles E. Extrinsic tongue muscles

D. Infrahyoid muscles

Which of the following muscle groups listed below is innervated but the cervical nerves? A. Muscles of mastication B. Muscles of facial expression C. Suprahyoid muscles D. Infrahyoid muscles E. Intrinsic tongue muscles

C. Infrahyoid muscles

Which of the following muscle groups listed below serves to depress the hyoid bone? A. Muscles of mastication B. Suprahyoid muscles C. Infrahyoid muscles D. Intrinsic tongue muscles E. Extrinsic tongue muscles

A. Superior longitudinal

Which of the following muscle pairs are considered to be intrinsic tongue muscles? A. Superior longitudinal B. Genioglossus C. Styloglossus D. Hyoglossus

D. Transverse

Which of the following muscle pairs is divided by a median septum? A. Geniohyoid B. Masseter C. Digastric D. Transverse E. Vertical

A. Palatoglossus

Which of the following muscles forms the anterior faucial pillar in the oral cavity? A. Palatoglossus B. Palatopharyngeus C. Stylopharyngeus D. Tensor veli palatini

A. Lateral pterygoid

Which of the following muscles has two bellies, giving the muscle two different origins? A. Lateral pterygoid B. Geniohyoid C. Thyrohyoid D. Stylohyoid

B. Hyoglossus muscle

Which of the following muscles is an extrinsic muscle of the tongue? A. Geniohyoid muscle B. Hyoglossus muscle C. Mylohyoid muscle D. Transverse muscle E. Vertical muscle

D. Masseter

Which of the following muscles is considered a muscle of mastication? A. Buccinator B. Rigorous C. Mental is D. Masseter E. Corrugator supercilii

C. Risorius

Which of the following muscles is used when a patient grimaces? A. Epicranial B. Corrugator supercilii C. Risorius D. Mentalis

D. Mandibular branch of the trigeminal nerve

Which of the following nerves innervates the temporalis muscles? A. First cervical nerve by way of the hypoglossal nerve B. Ninth cranial nerve or glossopharyngeal nerve C. Maxillary branch of the trigeminal nerve D. Mandibular branch of the trigeminal nerve E. Seventh cranial nerve or facial nerve

D. Mylohyoid

Which of the following paired muscles unite medially, forming the floor of the mouth? A. Geniohyoid B. Omohyoid C. Digastric D. Mylohyoid E. Transverse

B. Head flexes at the neck

Which of the following situations occurs when BOTH sternocleidomastoid muscles are used at the same time by the patient? A. Neck is drawn laterally B. Head flexes at the neck C. Chin moves superiorly to the contralateral side D. Head rotates and is drawn to the shoulders