Upper respiratory anatomy Part 3: The Larynx

Question 1

what are 4 functions of the larynx

Answer 1

• air passage
• sphincter to prevent aspiration of food and liquids
• organ of phonation
• raises intra abdominal pressure

Question 2

where does the larynx extend from

Answer 2

• C3 level to C6 level

Question 3

how many cartilages are in the larynx

Answer 3

9 cartilages

Question 4

what muscles allow the larynx to move up and down during swallowing

Answer 4

• extrinsic muscles originating from neighbouring structures and insert into the larynx

Question 5

what 2 things do intrinsic muscles do in the larynx

Answer 5

• move the vocal folds
• modifies the laryngeal inlet

Question 6

what are the 3 unpaired cartilages in the larynx

Answer 6

• cricoid cartilage
• thyroid cartilage
• epiglottis

Question 7

what are the 3 pairs of paired cartilages to add up to 9 cartilages total?

Answer 7

• arytenoid cartilages
• cuneiform cartilages
• corniculate cartilages

Question 8

Larynx: the membranes

what 2 things does the thyrohyoid membrane attach to ?

Answer 8

thyroid cartilage and hyoid bone

Question 9

what 3 things does the criocothyroid membrane attach to?

Answer 9

thyroid cartilage, cricoid cartilage and vocal processes of the arytenoid cartilage

Question 10

what does the upper free margin of the cricothyroid membrane form

Answer 10

the vocal ligaments

Question 11

true vocal folds

What cartilages do the vocal ligaments extend from

Answer 11

arytenoid cartilage to the thyroid cartilage

Question 12

what type of mucosa are vocal ligaments covered with and what does this help do

Answer 12

• covered with non-keratinized stratified squamous epithelial mucosa
• helps protect the tissue from mechanical stress on the surface of the vocal folds

Question 13

what makes up the true vocal folds

Answer 13

• mucosal covering
• vocal ligaments

Question 14

what movements of the vocal folds do the intrinsic muscles of the larynx allow and what does this open and close?

Answer 14

abduction and adduction

• opens and closes the rima glottidis

Question 15

when do the vocal folds fully abduct?

Answer 15

during forced inspiration

Question 16

if the posterior cricoarytenoids muscles fail to work or are paralysed what can result and why

Answer 16

results in asphyxiation as airway cannot open becasue posterior cricoarytenoids are the only muscles that can abduct the vocal folds

Question 17

what division of the vagus nerve supplies the criothyroid muscle and what division of the vagus nerve supplies all other laryngeal muscles

Answer 17

• the superior laryngeal branch division of the vagus nerve supplies the criothyroid muscle
• recurrent laryngeal branch of the vagus nerve supplies the rest

Question 18

what are 3 possible causes of bilateral lesion of the recurrent laryngeal nerve

Answer 18

• thyroid surgery
• cervical spinal surgery
• viral infection

Question 19

what are 2 general signs of bilateral lesion to the recurrent laryngeal nerve that you might see in a patient

Answer 19

near normal voice but respiratory distress (hypoxia, respiratory arrest or even death) due to a compromised airway