Upper respiratory anatomy Part 3: The Larynx Flashcards
what are 4 functions of the larynx
- air passage
- sphincter to prevent aspiration of food and liquids
- organ of phonation
- raises intra abdominal pressure
where does the larynx extend from
- C3 level to C6 level
how many cartilages are in the larynx
9 cartilages
what muscles allow the larynx to move up and down during swallowing
- extrinsic muscles originating from neighbouring structures and insert into the larynx
what 2 things do intrinsic muscles do in the larynx
- move the vocal folds
- modifies the laryngeal inlet
what are the 3 unpaired cartilages in the larynx
- cricoid cartilage
- thyroid cartilage
- epiglottis
what are the 3 pairs of paired cartilages to add up to 9 cartilages total?
- arytenoid cartilages
- cuneiform cartilages
- corniculate cartilages
Larynx: the membranes
what 2 things does the thyrohyoid membrane attach to ?
thyroid cartilage and hyoid bone
what 3 things does the criocothyroid membrane attach to?
thyroid cartilage, cricoid cartilage and vocal processes of the arytenoid cartilage
what does the upper free margin of the cricothyroid membrane form
the vocal ligaments
true vocal folds
What cartilages do the vocal ligaments extend from
arytenoid cartilage to the thyroid cartilage
what type of mucosa are vocal ligaments covered with and what does this help do
- covered with non-keratinized stratified squamous epithelial mucosa
- helps protect the tissue from mechanical stress on the surface of the vocal folds
what makes up the true vocal folds
- mucosal covering
- vocal ligaments
what movements of the vocal folds do the intrinsic muscles of the larynx allow and what does this open and close?
abduction and adduction
- opens and closes the rima glottidis
when do the vocal folds fully abduct?
during forced inspiration
if the posterior cricoarytenoids muscles fail to work or are paralysed what can result and why
results in asphyxiation as airway cannot open becasue posterior cricoarytenoids are the only muscles that can abduct the vocal folds
what division of the vagus nerve supplies the criothyroid muscle and what division of the vagus nerve supplies all other laryngeal muscles
- the superior laryngeal branch division of the vagus nerve supplies the criothyroid muscle
- recurrent laryngeal branch of the vagus nerve supplies the rest
what are 3 possible causes of bilateral lesion of the recurrent laryngeal nerve
- thyroid surgery
- cervical spinal surgery
- viral infection
what are 2 general signs of bilateral lesion to the recurrent laryngeal nerve that you might see in a patient
near normal voice but respiratory distress (hypoxia, respiratory arrest or even death) due to a compromised airway
