Download Superficial muscles of neck Platysma Attaches from inferior border of

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Superficial muscles of neck
o Platysma
 Attaches from inferior border of mandible to fascia covering superior parts of
pec major and deltoid muscles
 Innervated by cervical branch of facial nerve (CN VII)
 Draws corners of mouth inferiorly and widens it as in expressions of sadness and
fright; draws skin of neck superiorly when teeth are clenched
o Sternocleidomastoid
 Attaches from lateral surface of mastoid process of temporal bone and lateral
half of superior nuchal line to anterior surface of manubrium of sternum
(sternal head) and superior surface of medial third of clavicle (clavicular head)
 Spinal accessory nerve (CN XI, motor); C2 and C3 nerves
 Unilateral: tilts head to same side and rotates it so face is turned superiorly
toward opposite side
 Bilateral: extends neck at atlanto occipital joints, flexes cervical vertebrae so
chin approaches manubrium, extends superior cervical vertebrae while flexing
inferior vertebrae so chin is thrus forward
o Trapezius
 Attaches from medial third of superior nuchal line, external occipital
protuberance, nuchal ligament, spinous processes of C7-T12 vertebrae, and
lumbar and sacral spinous processes to lateral third of clavicle, acromion, and
spine of scapula
 Spinal accessory nerve (CN XI, motor); C2 and C3
Suprahyoid muscles
o Mylohyoid
 Myohyloid line of mandible -> mylohyoid raphe and body of hyoid
 Innervated by nerve to mylohyoid; a branch of the inferior alveolar nerve (CN
V3)
 Elevates hyoid, floor of mouth, and tongue during swallowing and speaking
o Geniohyoid
 Inferior mental spine of mandible -> body of hyoid
 Innervated by C1 via hypoglossal nerve (CN XII)
 Pulls hyoid anterosuperiorly; shortens floor of mouth; widens pharynx
o Stlyohyoid
 Styloid process of temporal bone -> body of hyoid
 Innervated by stylohyoid branch of facial nerve (CN VII)
 Elevates and retracts hyoid; elongates floor of mouth
o Digastric
 Digastric fossa of mandible (anterior), mastoid notch of temporal bone
(posterior) -> intermediate tendon to body and greater horn of hyoid
 Innervated by nerve to mylohyoid (anterior) and digastric branch of facial nerve
(posterior)
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Depresses mandible against resistance; elevates and steadies hyoid during
swallowing and speaking
Infrahyoid muscles
o Sternohyoid
 Manubrium of sternum and medial clavicle -> body of hyoid
 Innervated by C1-3 through a branch of ansa cervicalis
 Depresses hyoid after elevation during swallowing
o Omohyoid
 Superior border of scapula near suprascapular notch -> inferior border of hyoid
 Innervated by C1-3 through a branch of ansa cervicalis
 Depresses, retracts, and steadies hyoid
o Sternothyroid
 Posterior surface of manubrium -> oblique line of thyroid cartilage
 Innervated by C2-3 through branch of ansa cervicalis
 Depresses hyoid and larynx
o Thyrohyoid
 Oblique line of thyroid cartilage -> inferior border of body and greater horn of
hyoid
 Innervated by C1 via hypoglossal nerve
 Depresses hyoid and elevates larynx
Prevertebral muscles
o Anterior scalene
 Transverse processes of C4-6 -> 1st rib
 Cervical spinal nerves C4-6
 Flex head
o Levator scapulae
 Posterior tubercles of transverse processes C1-4 vertebrae -> superior part of
medial border of scapula
 Dorsal scapular nerve C5 and cervical spinal nerves C3,4
 Elevates scapula and tilts its glenoid cavity inferiorly
o Middle scalene
 Posterior tubercles of transverse processes of C4-6 -> superior border of 1st rib;
posterior groove for subclavian artery
 Anterior rami of cervical spinal nerves
 Flexes neck laterally; elevates 1st rib during forced inspiration
o Posterior scalene
 Posterior tubercles of transverse processes of C4-6 -> external border of 2nd rib
 Anterior rami of cervical spinal nerves C7,8
 Flexes neck laterally; elevates 2nd rib during forced inspiration
Muscles of face/scalp
o Occipitofrontalis
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Frontal belly
 Epicranial aponeurosis -> skin and subcutaneous tissue of eyebrows and
forehead
 Elevates eyebrows and wrinkles skin of forehead; protracts scalp
(surprise)
 Temporal branch of parotid plexus
 Occipital belly
 Lateral two thirds of superior nuchal line -> epicranial aponeurosis
 Retracts scalp, increasing effectiveness of frontal belly
 Posterior auricular branch of CN VII
o Orbicularis oculi
 Medial orbital margin; medial palpebral ligament; lacrimal bone -> skin around
margin of orbit; superior and inferior tarsal plates
 Closes eyelids; palpebral does so weakly; oribital does so tightly
 Temporal and zygomatic branches of parotid plexus
o Orbicularis oris
 Medial maxilla and mandible; deep surface of perioral skin; angle of mouth ->
mucous membrane of lips
 Tonus closes rima oris; phasic contraction compresses and protrudes lips
(kissing) or resists distension (blowing)
 Buccal branch of parotid plexus
o Buccinator
 Mandible, alveolar processes of maxilla and mandible, pterygomandibular raphe
-> angle of mouth; orbicularis oris
 Presses cheek against molar teeth; works with tongue to keep food between
occlusal surfaces and out of oral vestibule; resists distension (blowing)
 Buccal branch of parotid plexus
o Platysma
 Subcutaneous tissue of infraclavicular and supraclavicular regions -> base of
mandible; skin of cheek and lower lip; angle of mouth; orbicularis oris
 Depresses mandible; tenses skin of inferior face and neck
Extraocular muscles of the orbit
o Levator palpebrae superioris
 Oculomotor nerve; deep layer is supplied by sympathetic fibers
 Elevates superior eyelid
o Superior oblique
 Trochlear nerve (CN IV)
 Abducts, depresses, and medially rotates eyeball
o Inferior oblique
 Oculomotor nerve (CN III)
 Abducts, elevates, and laterally rotates eyeball
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Superior rectus
 Oculomotor nerve (CN III)
 Elevates, adducts, and rotates eyeball medially
o Inferior rectus
 Oculomotor nerve (CN III)
 Depresses, adducts, and rotates eyeball medially
o Medial rectus
 Oculomotor nerve (CN III)
 Adducts eyeball
o Lateral rectus
 Abducent nerve (CN VI)
 Abducts eyeball
Muscles of mastication
o Temporal
 Floor of temporal fossa -> tip and medial surface of coronoid process and
anterior border of ramus of mandible
 Mandibular nerve via deep temporal branches
 Elevates mandible; posterior, more horizontal fibers are primary retractors of
mandible
o Masseter
 Inferior border and medial surface of maxillary process -> angle and lateral
surface of ramus of mandible
 Mandibular nerve via masseteric nerve
 Elevates mandible; superficial fibers make limited contribution to protrusion of
mandible
o Lateral pterygoid
 Infratemporal surface and crest of greater wing of sphenoid and lateral surface
of lateral pterygoid plate -> upper head attaches to joint capsule and articular
disc of TMJ; inferior head attaches to pterygoid fovea on anteriomedial aspect
of neck of condyloid process of mandible
 Mandibular nerve via lateral pterygoid nerves
 Bilaterally: protracts mandible and depresses chin; unilaterally: swings jaw
towards contralateral side; large lateral chewing movements produced by
alternating unilateral contractions
o Medial pterygoid
 Medial surface of lateral pterygoid plate and pyramidal process of palatine bone
and tuberosity of maxilla -> medial surface of ramus of mandible
 Mandibular nerve via medial pterygoid nerve
 Synergistic with masseter to elevate mandible; contributes to protrusion; small
grinding movements produced by alternate unilateral activity
Muscles of the soft palate
o Tensor veili palatine
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Medial pterygoid nerve (branch of CN V3) via otic ganglion
Tenses soft palate and opens mouth of pharyngotympanic tube during
swallowing and yawning
o Levator veli palatini
 Pharyngeal branch of vagus nerve via pharyngeal plexus
 Elevates soft palate during swallowing and yawning
o Palatoglossus
 Pharyngeal branch of vagus nerve via pharyngeal plexus
 Elevates posterior part of tongue and draws soft palate onto tongue
o Palatopharyngeus
 Pharyngeal branch of vagus nerve via pharyngeal plexus
 Tenses soft palate and pulls walls of pharynx superiorly, anteriorly, and medially
during swallowing
o Musculus uvulae
 Pharyngeal branch of vagus nerve via pharyngeal plexus
 Shortens uvula and pulls it superiorly
Extrinsic muscles of the tongue
o Genioglossus
 Tendon from superior part of mental spine of mandible -> entire dorsum of
tongue; inferior most and posterior most fibers attach to body of hyoid bone
 Bilaterally: depresses tongue, especially central part causing a longitudinal
furrow; posterior part pulls tongue anteriorly for protrusion; most anterior part
retracts apex of protruded tongue; unilateral contraction deviates tongue to
contralateral side
 Hypoglossal nerve (CN XII)
o Hyoglossus
 Body and greater horn of hyoid bone -> inferior aspects of lateral part of tongue
 Depresses tongue, especially pulling its sides inferiorly; helps shorten tongue
 Hypoglossal nerve (CN XII)
o Styloglossus
 Anterior border of distal styloid process; stylohyoid ligament -> sides of tongue
posteriorly, interdigitating with hyoglossus
 Retrudes tongue and curls its sides working with genioglossus to form a central
trough during swallowing
 Hypoglossal nerve (CN XII)
o Palatoglossus
 Palatine aponeurosis -> enters posterolateral tongue transversely, blending with
intrinsic transverse muscles
 Capable of elevating posterior tongue or depressing soft palate; most commonly
acts to constrict isthmus of fauces
 Vagus nerve
Muscles of the larynx
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Cricothyroid
 Anterolateral part of cricoids cartilage -> inferior margin and inferior horn of
thyroid cartilage
 External laryngeal nerve (CN X)
 Stretches and tenses vocal ligament
o Thyroarytenoid
 Lower half of posterior angle of thyroid laminae and cricothyroid ligament ->
anterolateral arytenoid surface
 Inferior laryngeal nerve (terminal recurrent from CN X)
 Relaxes vocal ligament
o Posterior cricoarytenoid
 Posterior surface of lamina of cricoids cartilage -> vocal process of arytenoid
cartilage
 Inferior laryngeal nerve (terminal recurrent from CN X)
 Abducts vocal folds
o Lateral cricoarytenoid
 Arch of cricoids cartilage -> vocal process of arytenoid cartilage
 Inferior laryngeal nerve (terminal recurrent from CN X)
 Adducts vocal folds (interligamentous portion)
o Transverse and oblique arytenoids
 One arytenoid cartilage -> contralateral arytenoid cartilage
 Inferior laryngeal nerve (terminal recurrent from CN X)
 Adduct arytenoid cartilages (adducting intercartilagenous portion of vocal folds,
closing posterior rima glottidis)
o Vocalis
 Lateral surface of vocal process of arytenoid cartilage -> ipsilateral vocal
ligament
 Inferior laryngeal nerve (terminal recurrent from CN X)
 Relaxes posterior vocal ligament while maintaining (or increasing) tension of
anterior part
Muscles of pharynx
o External layer
 Superior constrictor
 Pterygoid hamulus, pterygomandibular raphe; posterior end of
mylohyoid line of mandible and side of tongue -> pharyngeal tubercle
on basilar part of occipital bone
 Pharyngeal branch of vagus
 Constrict walls of pharynx during swallowing
 Middle constrictor
 Stylohyoid ligament and greater and lesser horns of hyoid -> pharyngeal
raphe
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Pharyngeal branch of vagus + branches of external and recurrent
laryngeals
 Constrict walls of pharynx during swallowing
 Inferior constrictor
 Oblique line of thyroid cartilage and side of cricoids cartilage ->
pharyngeal raphe, cricopharyngeal part encircles pharyngoesophageal
junction without forming a raphe
 Pharyngeal branch of vagus + branches of external and recurrent
laryngeals
 Constrict walls of pharynx during swallowing
Internal layer
 Palatopharyngeus
 Hard palate and palatine aponeurosis -> posterior border of lamina of
thyroid cartilage and side of pharynx and esophagus
 Pharyngeal branch of vagus
 Elevate (shorten and widen) pharynx and larynx during swallowing and
speaking
 Salpingopharyngeus
 Cartilaginous part of pharyngotympanic tube -> blends with
palatopharyngeus
 Pharyngeal branch of vagus
 Elevate (shorten and widen) pharynx and larynx during swallowing and
speaking
 Stylopharyngeus
 Styloid process of temporal bone -> posterior and superior borders of
thyroid cartilage and palatopharyngeus
 Glossopharyngeal nerve
 Elevate (shorten and widen) pharynx and larynx during swallowing and
speaking