CSD532 A+P 3

larynx

• passageway between upper and lower airway

• both conscious and autonomic control

• sphincter, thoracic fixation, phonation

laryngeal structure contains

• hyoid bone

• cartilages

• joints

• connective tissues

• cavities

• vocal folds

• intrinsic and extrinsic muscles

hyoid bone

• anchors musculature

• greater cornu, lesser cornu, and body

thyroid cartilage

• laminae (2)

• superior cornu (2)

  • attaches to the hyoid bone via ligaments 

• inferior cornu (2)

  • connects thyroid to the cricoid via joint

• oblique line (2)

• superior thyroid notch

• inferior thyroid notch

• laryngeal prominence

• anterior angle

cricoid cartilage

• signet ring shaped

• attaches to first tracheal ring

• base for thyroid movement

arytenoid joint movement

• abduction and adduction

• pivots medially/laterally

• slides medially/laterally

• rocks posteriorly/anteriorly

other cartilages

• corniculate

• cuneiform

hyaline cartilage

• flexible and elastic

• composed of collagen and other proteins

• forms thyroid, cricoid, and arytenoid cartilages

• ossifies with age

elastic cartilage

• matrix contains collagenous fibers and branched yellow elastic fibers

• does not ossify

• forms the eppigotis

ligaments

• thryoepiglottic

• hyoepiglottic

• vestibular/ventricular

• glossoepiglottic

• vocal

folds/cavities

• ventricular/vestibular folds/false vocal folds

• ventricles

• aryepiglottic folds

• laryngeal vestibule

• supraglottis

• glottis

• infraglottis/subglottis

aryepiglottic folds

• lateral anatomical border of the laryngeal space

• withstands collapse during inspiration

cavities/spaces

• posterior commissure

• anterior commissure

• glottis

intrinsic laryngeal muscles

• within the larynx

• tension of vocal fold

• size and shape of glottal space

• movements of laryngeal cartilages

• finer control of laryngeal structures

thyroarytenoid

• contracts to shorten vocal folds

• thyrovocalis: tenses vf when contracted

• thyromuscularis: relaxes vf when contracted

posterior cricoarytenoid

abducts vocal folds

lateral cricoarytenoid

adducts vocal folds

cricothyroid

changes pitch when contracted

interarytenoids

• oblique and transverse fibers

• with contraction, adducts the vocal folds more completely

other muscles

• aryepiglottic muscle

• ventricular muscle

extrinsic laryngeal muscles

• laryngeal elevation

  • suprahyoids

• laryngeal depression

  • infrahyoids

suprahyoids

• digastric

• mylohyoid

• stylohyoid

• geniohyoid

infrahyoids

• sternohyoid

• sternothyroid

• omohyoid

• thyrohyoid

neurological control of the larynx

• involuntary sounds

  • Midbrain – periaqueductal grey

  • Perisylvian regions of cortex

  • Brainstem nuclei

• intentional speech

  • Cortical and subcortical regions

  • Pyramidal and extrapyramidal pathways

neurological control of speech production

• Motor Plan/Programming

  • Premotor cortex

  • Auditory cortical regions

  • Subcortical regions

  • Brainstem

• Execution

  • Primary motor cortex – pyramidal

  • Extrapyramidal – muscle tone

vagus nerve

•  “Wandering”

  • Innervates from skull to abdomen

  • Afferent, efferent, and parasympatheic fibers

• nuclei in medulla

superior laryngeal nerve

• Internal branch 

  • inserts through thyrohyoid membrane (above the TVF)

  • sensory information to the larynx

• External branch

  • motor innervation to cricothyroid muscle  

  • possibly also innervates ipsilateral thyroiarytenoid muscle, inferior pharyngeal constrictor, and upper esophageal sphincter

recurrent laryngeal nerve

• Different paths on each side

• Sensory information below the vocal folds

• Motor innervation to the intrinsic muscles except CT