a&p - exam 2 muscles (o/ins/inv/funtion)

lateral cricoartenoid

INTRINSIC ADDUCTOR

origin: anterolateral surface of cricoid arch

insertion: muscular process, anterior surface of arytenoid

innervation: CN X, RLN (recurrent laryngeal nerve)

function: moves muscular process anteriorly; for adduction, it participates in rotating arytenoid bringing vocal process toward midline; increases medial compression

transverse arytenoid

INTRINSIC ADDUCTOR

origin: lateral-posterior margin of one arytenoid

insertion: lateral-posterior margin of opposite arytenoid

innervation: CN X, inferior branch of RLN (recurrent laryngeal nerve)

function: contraction causes arytenoids to slide along long axis toward midline; medial compresses vocal fold; pulls arytenoids closer

oblique artenoid

INTRINSIC ADDUCTOR

origin: posterolateral surface of muscular process; adjacent surface

insertion: apex of opposite arytenoid

innervation: CN X, RLN (recurrent laryngeal nerve)

function: pulls apex medially which approximates arytenoids; regulates medial compression

posterior cricoarytenoid

INTRINSIC ABDUCTOR

origin: posterior cricoid lamina

insertion: posterior aspect of muscular process of arytenoid cartilage

innervation: CN X, RLN

function: rocks arytenoid cartilage laterally, abductor; medial part acts to stabilize and fix arytenoid

cricothyroid (pars recta)

INTRINSIC TENSOR

origin: anterior surface of cricoid beneath the arch

insertion: lower surface of the thyroid lamina

innervation: CN X, external branch of SLN (superior laryngeal nerve)

function: actively tenses or elongates vocal folds (increases distance between thyroid and vocal process, which elongates vocal fold and increases its tension); depresses thyroid relative to cricoid

cricothyroid (pars oblique)

INTRINSIC TENSOR

origin: cricoid cartilage lateral to pars recta

insertion: thyroid cartilage between laminae and inferior horns

innervation: CN X, external branch of SLN (superior laryngeal nerve)

function: actively tenses or elongates vocal folds (increases distance between thyroid and vocal process, which elongates vocal fold and increases its tension); depresses thyroid relative to cricoid

thyroartenoid muscle

composed of thyrovocalis and thyromuscularis

acts as a regulator of longitudinal tension

thyrovocalis

INTRINSIC TENSOR

origin: inner surface, angle of thyroid

insertion: course back to lateral-inferior aspect of arytenoid vocal process

innervation: X vagus, RLN (recurrent laryngeal nerve)

function: tenses vocal folds (when opposed by other intrinsic muscles)

thyromuscularis

INTRINSIC RELAXER

origin: inner surface, angle of thyroid

insertion: swing-off lateroposterosuperior direction into base and muscular process of arytenoid

innervation: X vagus, RLN (recurrent laryngeal nerve)

function: relaxes vocal fold, adduction

thyroepiglottic

INTRINSIC AUXILLARY MUSCLE

origin: inner surface, thyroid angle

insertion: lateral epiglottis

innervation: X vagus, RLN (recurrent laryngeal nerve)

function: dilates the laryngeal opening; compresses laryngeal saccule for mucus secretion

aryepiglottic

INTRINSIC AUXILLARY MUSCLE

origin: continuation of oblique arytenoid from apex

insertion: lateral epiglottis

innervation: X vagus, RLN (recurrent laryngeal nerve)

function: deflects epiglottis over airway opening to help protect the airway during swallowing; constricts laryngeal opening

digastric - anterior belly

EXTRINSIC SUPRAHYOID

origin: inner surface of mandible, near symphysis

insertion: hyoid via intermediate tendon

innervation: CN V (trigeminal), inferior alveolar nerve

function: pulls hyoid up and forward

digastric - posterior belly

EXTRINSIC SUPRAHYOID

origin: mastoid process of temporal bone

insertion: hyoid via intermediate tendon

innervation: CN VII (facial), digastric branch

function: pulls hyoid up and back

stylohyoid

EXTRINSIC SUPRAHYOID

origin: posterior/lateral (styloid) process of temporal bone

insertion: splits into 2 slips passing around intermediate tendon to insert into corpus of hyoid

innervation: CN VII (facial), stylohyoid branch

function: contraction draws hyoid up and backward, moving it posteriorly

mylohyoid

EXTRINSIC SUPRAHYOID

origin: inner bony ridge of mandible (mylohyoid line)

insertion: midline raphe; posterior-most attach to corpus of hyoid

innervation: CN V (trigeminal), mylohyoid branch from inferior alveolar nerve

function: elevates hyoid, floor of mouth, and tongue; with hyoid in a fixed position, it assists in depressing the mandible

geniohyoid

EXTRINSIC SUPRAHYOID

origin: short tendon from mental symphysis of mandible

insertion: corpus of hyoid

innervation: C1 spinal nerve via CN XII (hypoglossal)

function: elevate and draw hyoid forward

hyoglossus

EXTRINSIC SUPRAHYOID

origin: greater horns and body of hyoid

insertion: posterior, lateral portion of tongue

innervation: CN XII (hypoglossal, motor branch

function: elevates hyoid, lingual depressor; influences position of larynx indirectly

genioglossus

EXTRINSIC SUPRAHYOID

origin: mental symphysis of mandible

insertion: lowermost fibers of corpus of hyoid; upper dorsum and tip of tongue

innervation: CN XII (hypoglossal), motor branch

function: extrinsic tongue muscle; contraction elevates hyoid

sternohyoid

EXTRINSIC INFRAHYOID

origin: manubrium sterni, clavicle

insertion: inferior margin of hyoid corpus

innervation: ansa cervicalis, C1-C3

function: draws hyoid down; fixes hyoid when lower jaw is opened against resistance

omohyoid - superior

EXTRINSIC INFRAHYOID

origin: intermediate tendon

insertion: lower border, greater horn of hyoid

innervation: ansa cervicalis C1

function: depresses hyoid; prevents neck region from collapsing during deep inspiratory efforts

omohyoid - inferior

EXTRINSIC INFRAHYOID

origin: upper border scapula

insertion: intermediate tendon, just above the sternum

innervation: ansa cervicalis, C2-C3

function: depresses hyoid; prevents neck region from collapsing during deep inspiratory efforts

sternothyroid

EXTRINSIC INFRAHYOID

origin: posterior surface of manubrium sterni & 1st costal cartilage

insertion: oblique line of thyroid

innervation: XII hypoglossal and spinal nerves C1 and C2

function: draw thyroid cartilage down

thryohyoid

EXTRINSIC INFRAHYOID

origin: oblique line of thyroid lamina

insertion: lower border of greater horn of hyoid

innervation: spinal nerve C1 via CN XII (hypoglossal)

function: contraction decreases distance between thyroid and hyoid; thyroid fixed = depresses hyoid; hyoid fixed = elevates thyroid

superior pharyngeal constrictor

OUTER CIRCULAR LAYER

origin: hamulus, pterygomandibular raphe; mylohyoid line, mandible

insertion: median raphe, pharyngeal tubercle

innervation: CN X via pharyngeal plexus

function: pull pharyngeal wall forward to assist in closing nasopharynx; narrows the upper pharyngeal segment

middle pharyngeal constrictor

OUTER CIRCULAR LAYER

origin: stylohyoid ligament, horns of hyoid bone

insertion: median raphe, pharynx

innervation: CN X via pharyngeal plexus

function: narrows diameter of mid portion of pharynx

inferior pharyngeal constrictor muscle consists of…

thyropharyngeus & cricopharyngeus

thyropharyngeus

origin: oblique line of thyroid lamina and inferior cornu

insertion: median raphe

innervation: CN X via pharyngeal plexus

function: constricts lower pharynx, elevates larynx

cricopharyngeus

aka upper esophageal sphincter

origin: cricoid

insertion: median raphe

innervation: CN X via pharyngeal plexus; external LN and RLN motor CN X

function: conform sphincter like tube

salpingopharyngeus

INNER LONGITUDINAL LAYER

origin: auditory tube

insertion: lateral pharyngeal wall (converges with palatopharyngeus muscle)

innervation: CN X via pharyngeal plexus

function: elevates lateral pharyngeal wall

palatopharyngeus

INNER LONGITUDINAL LAYER

origin: posterior border of hard palate; palatine aponeurosis

insertion: posterior border of the lamina of the thyroid cartilage

innervation: CN X via pharyngeal plexus

function: narrow pharynx; acts as sphincter to lower the palate and decrease distance between arches (swallowing and gagging)

stylopharyngeus

INNER LONGITUDINAL LAYER

origin: styloid process of temporal bone

insertion: lateral pharyngeal wall

innervation: CN IX (glossopharyngeal)

function: elevates and opens pharynx, especially during deglutition

pharyngeal plexus nerve

formed by pharyngeal branches of the glossopharyngeal nerve and vagus nerve & superior cervical ganglion

innervates muscles of pharynx (except stylopharyngeus)