Larynx Flashcards
where is the larynx located
level of bodies of C3-C6 extending from tip of epiglottis to the inferior border or cricoid cartilage
4 functions of pharynx
- connects oropharynx to trachea and permits air passage to trachea
- protective sphincter to airway
- organ of phonation
- elevation of it is crucial in swallowing
function of larynx in swallowing
elevation of larynx is crucial in swallowing
laryngopharynx is continuous with what
oesophagus
describe cartilage in larynx
all hyaline cartilage except epiglottis which is elastic
which cartilage forms a complete ring
cricoid cartilage
how does the thyroid cartilage attach to the hyoid bone
by thyrohyoid membrane attaching from superior and inferior horn
at the inferior horn, the thyroid cartilage articulates with what
cricoid cartilage
what happens when thyroid and cricoid cartilages articulate
changes length of vocal cords and thus pitch of the voice
what is the cricoid cartilage divided into posteriorly and anteriorly
posteriorly - lamina of cricoid
anteriorly - arch of cricoid
cricoid attachments superiorly and inferiorly
inferiorly to 1st tracheal ring by cricotracheal ligament
superiorly to thyroid cartilage by cricothyroid ligament
importance of cricothyroid ligament
site where emergency airway can be established
2 attachments of epiglottis
- to thyroid cartilage via thyro-epiglottic ligament
- to hyoid bone via hyo-epiglottic ligament
function of epiglottis
to close airway to facilitate deglutition i.e. not essential for respiration or phonation
arytenoid cartilage function
articulate with lamina of cricoid cartilage to form cricoarytenoid joints and is essential for phonation
where does the quadrangular membrane span
from arytenoid cartilage to thyroid cartilage in epiglottis
connection between quadrangular membrane and vestibular fold
free inferior margin constitutes vestibular ligament which is covered loosely by mucosa to form the vestibular fold that lies superior to the vocal fold
superior free margin of quadrangular membrane forms
aryepiglottic ligament which is covered with mucosa to form aryepiglottic fold
cricothyroid ligament runs from where to where
from cricoid to arytenoid to thyroid cartilage
function of aryepiglottic fold
forms laryngeal inlet which is the protective sphincter of larynx
vocal folds
control sound production from larynx - these are the true vocal cords
what is the aperture between the vocal folds known as
rima glottis
intrinsic laryngeal muscles (3)
- open / close rima glottis (abductors / adductors)
- alter the tension of the vocal folds (true vocal cords) tensors / relaxers
- open or close the laryngeal inlet (sphincter muscles)
extrinsic laryngeal muscles
infra and suprahyoid muscles as well as stylopharyngeus
infrahyoid - depress hyoid and larynx
suprahyoid & stylopharyngeus - elevate hyoid and larynx
muscles that open and close rima glottidis
lateral cricoarytenoid - adduction
posterior cricoarytenoid - abduction
lengthened vocal cords =
increased tension = higher pitch
shortened vocal cords =
reduced tension = lower pitch
muscles that cause pitch change
tensors = cricothyroid muscles
relaxers = thryoarytenoid muscles
these pull on their respective cartilages
opening of laryngeal inlet is via
depression of larynx which can be felt to an extent during swallowing
closure of laryngeal inlet is via
oblique arytenoid muscle
motor supply of larynx
vagus nerve via recurrent laryngeal nerve except for cricothyroid which is supplied by external branch of superior laryngeal nerve
sensory supply of larynx
above the vocal folds is by internal branch of superior laryngeal nerve
below the vocal folds is via recurrent laryngeal nerve
both branches of CN X
in quiet respiration
vocal & vestibular folds are abducted
a triangular ‘open’ rima glottidis
in forced inspiration
rima glottidis more forcefully and widely opened by posterior cricoarytenoid muscle
during normal repsiration
laryngeal muscles are relaxed and rima glottidis assumes a narrower, triangle position
during deep inhalation
vocal ligaments abducted by contraction of posterior cricoarytenoid muscles which forcefully opens rima glottidis into inverted kite shape
for speech production
vocal folds adducted
rima glottidis closed & air forced through causing vibration thus producing tone
vocal fold length & tension, for pitch and voice altered by cricothyroid & thyroarytenoid
in effort closure for e.g. heavy lifting
vocal & vestibular folds adducted
rima glottidis is closed
vestibule is closed
for swallowing
epiglottis is involved and swings down to arytenoids as the laryngeal inlet is narrowed and larynx elevated
