Superficial Face/Muscles of Mastication, Larynx and Pharynx Flashcards
Buccinator
Cheek Muscle
Innervation: Facial Nerve (CN VII) via Buccal Branches
Action:
Presses cheek against molar teeth; works with tongue to keep food between occlusal surfaces and out of oral vestibule; resists distention (when blowing)
Occipitofrontalis (Frontal Belly)
Innervation: Facial Nerve (CN VII) via Temporal branch
Action:
Elevates eyebrows and wrinkles skin of forehead; protracts scalp (indicating surprise or curiosity)
Orbicularis Oculi (Orbital Sphincter)
Innervation: Facial Nerve (CN VII) via Temporal Branch
Action:
Closes eyelids: palpebral part does so gently; orbital part tightly (winking)
Orbicularis Oris (Oral Sphincter)
Innervation: Facial Nerve (CN VII) via Buccal Branch
Action:
Tonus closes mouth; phasic contraction compresses and protrudes lips (kissing) or resists distention (when blowing)
Masseter
Muscle of Mastication
Origin:
Quadrate muscle attaching to inferior border and medial surface of maxillary process of zygomatic bone and the zygomatic arch
Insertion:
Angle and lateral surface of ramus of mandible
Innervation:
Anterior trunk of mandibular nerve (CN V3); Via Masseteric Nerve
Action:
Elevates mandible; superficial fibers make limited contribution to protrusion of mandible
Temporalis
Muscle of Mastication
Origin:
Triangular muscle with broad attachment to floor of temporal fossa and deep surface of temporalis fascia
Insertion:
Narrow attachment to tip and medial surface of coronoid process and anterior border of ramus of mandible
Innervation:
Anterior trunk of mandibular nerve (CN V3); Via Deep Temporal Nerves
Action:
Elevates mandible, closing jaws; posterior, more horizontal fibers are retractors of mandible
Occipitofrontalis (Occipital belly)
Innervation: Facial Nerve (CN VII) via Posterior auricular branch
Action:
Retracts scalp; increasing effectiveness of frontal belly
Facial Nerve (CN VII)
Branches:
temporal, zygomatic, buccal, marginal
mandibular, cervical.
Trigeminal Nerve (CN V)
Function:
The Sensory nerve for Face
The Motor nerve for muscles of mastication.
Branches:
supraorbital,
infraorbital, mental (branches of V1, V2,
and V3 respectively)
Platysma
Innervation: Facial Nerve (CN VII) via Cervical Branch
Action: Depresses mandible (against resistance); tenses skin of inferior face and neck (conveying tension and stress)
Lateral Pterygoid
Origin:
Triangular 2-headed muscle from (1) Infratemporal surface and crest of greater wing of sphenoid and (2) Lateral surface of lateral pterygoid plate
Insertion:
Superior head attaches primarily to joint capsule and articular disc of TMJ; Inferior head attaches primarily to pterygoid fovea on anteromedial aspect of neck of condyloid process of mandible
Innervation:
Anterior trunk of mandibular nerve (CN V3) via nerves to lateral pterygoid
Action:
Acting bilaterally, protracts mandible and depresses chin; acting unilaterally, swings jaw toward contralateral side; alternate unilateral contraction produces larger lateral chewing movements
Medial Pterygoid
Origin:
Quadrangular 2-headed muscle from (1) medial surface of lateral pterygoid plate and pyramidal process of palatine bone and (2) tuberosity of maxilla
Insertion:
Medial surface of ramus of mandible, inferior to mandibular foramen; in essence, a “mirror image” of the ipsilateral masseter, the 2 muscles flanking the ramus
Innervation:
Anterior trunk of mandibular nerve (CN V3) via nerve to medial pterygoid.
Action:
Acts synergistically with masseter to elevate mandible; contributes to protrusion; alternate unilateral activity produces smaller grinding movements
Superior Pharyngeal Constrictor
External Layer of Pharynx
Innervation:
Pharyngeal branch of Vagus (CN X) and pharyngeal plexus.
Action:
Constrict walls of Pharynx during swallowing
Middle and Inferior Pharyngeal Constrictors
External Layer of Pharynx
Innervation:
Pharyngeal branch of Vagus (CN X) and pharyngeal plexus, plus branches of external and recurrent laryngeal nerves of vagus.
Action:
Constrict walls of Pharynx during swallowing
Stylopharyngeus
Internal Layer of Pharynx muscles
Innervation: Glossopharyngeal nerve (CN IX)
Action:
Elevate (shorten and widen) pharynx and larynx during swallowing and speaking
Nasopharynx
Posterior to the nose and superior to the soft palate
Has respiratory function
Oropharynx
Posterior to the mouth
Has disgestive function
Laryngopharynx
Posterior to the larynx
Runs from C4-C6.
Epiglottis
Heart shaped cartilage covered with mucous membrane. Situated posterior to the root of the tongue and the hyoid anterior to the laryngeal inlet.
Larynx
Function:
Voice Production
Location:
C3-C6 vertebrae
Connects pharynx with trachea
Thyroid Cartilage
The largest of the cartilages.
Superior border lies opposite to the C4 Vertebrae.
Cricoid Cartilage
Forms a complete ring around the airway, the only cartilage of the respiratory tract to do so.
Smaller but thicker and stronger than thyroid cartilage
Lies at C6
Arytenoid Cartilage
Paired, three-sided pyramidal cartilages that articulate with lateral parts of the superior border of the cricoid cartilage lamina.
Laryngeal Vestibule
Between the laryngeal inlet and vestibular folds
Laryngeal Ventricle
Recesses extending laterally from the middle part of the laryngeal cavity between vestibular and vocal folds.
Vocal Folds (true vocal cords)
Control sound production.
The source of sounds (tone) that come from the larynx.
Glottis
Vocal apparatus of the larynx. makes up vocal folds and processes, together with the rima glottidis.
Vestibular folds
False vocal cords.
Have little to no role in voice production.
Function is to Protect.
Extending between the posterior aspect of the laryngeal prominence and arytenoid cartilages.
Cricothyroid Muscle
Innervation:
External Laryngeal nerve from CN X
Action:
Stretches and tenses vocal ligament.
Posterior Cricoarytenoid Muscle
Innervation:
Inferior laryngeal nerve (terminal part of recurrent laryngeal nerve, from CN X)
Action:
Abducts Vocal Cords
Internal Laryngeal Nerve
The larger terminal branch of the superior laryngeal nerve. Pierces thyroid membrane with superior laryngeal artery,
supplying fibers to the laryngeal mucous membrane of the laryngeal vestibule and middle laryngeal cavity including superior surface of vocal folds.
External Laryngeal Nerve
Descends posterior to the sternothyroid muscle in company with the superior thyroid artery
Supplies cricothyroid muscle
Inferior laryngeal nerve
A continuation of the recurrent laryngeal nerve (a branch of the vagus nerve)
Supplies all intrinsic muscles of the larynx except the cricothyroid, which is supplied by the external laryngeal nerve.
