10.1.3 Muscles and Movements of the Larynx

Question 1

Why does the pharynx collpase?

Answer 1

Has no cartilage, only opens up when it filled with food/fluid

Question 2

What are the functions of the intrinsic laryngeal muscles?

Answer 2

• Alter size and shape of laryngeal inlet
• Alter tension in and position of true vocal cords

Question 3

How do Intrinsic Laryngeal muscles alter the size and shape of laryngeal inlet?

Answer 3

Muscles within aryepiglottic folds contract ,narrows laryngeal inlet and flattens epiglottis

Protects larynx during swallowing

Question 4

How do intrinsic laryngeal muscles alter tension and position true vocal cords?

Answer 4

Muscles within larynx alter position of arytenoid cartilages- vary position of cords, adducted during swallowing

Protects larynx during swallowing and enables phonation (vocal cords vibrate as hit by air)

Question 5

What are all intrinsic laryngeal muscles supplied by?

Answer 5

Supplied by the recurrent laryngeal branch of vagus

Left vagus supplies left, vive.

Question 6

What intrinsic laryngeal muscle is not supplied by recurrent laryngeal branch?

Answer 6

Cricothyroid, supplied by external branch of superior laryngeal nerve

Question 7

What happens to bolus during swallowing

Answer 7

Goes into piriform fossae away from laryngeal inlet where it drains into pharynx

Question 8

Where do vocal cords run from and go to?

Answer 8

Arytenoid cartilage to inner surface of thyroid

Question 9

How do vocal cords move?

Answer 9

Arytenoid cartilages move, widening rima glottidis, connection to thyroid is fixed

Question 10

How do the majority of muscles act on rima glottidis?

Answer 10

Narrow rima glottidis by adducting VCs together

Only posterior cricoarytenoid abducts which allows widening of rima glottidis

Question 11

What is the function of intrinsic muscles of the larynx in relation to arytenoids?

Answer 11

Arytenoids move relative to one another (on cricoid cartilage)

Alters position of true VCs and therefore size of rima glottidis

Question 12

What is the position of the VCs while breathing?

Answer 12

abducted
b-breathing
Laryngeal inlet also open

Question 13

What is the position of the VCs while swallowing?

Answer 13

Adducted, laryngeal inlet also narrowed by muscles in aryepiglottic folds

Question 14

What is the position of true VCs in Phonation?

Answer 14

Adducted close together with small gap - allows air through small gap creating vibration of VCs creating sound waves

Question 15

What is the position of VC during coughing?

Answer 15

VC adducted, pressure increases in thoracic cavity
Snaps open (abducts) when air is forced through fast

Question 16

What determines pitch of the voice?

Answer 16

Tension in vocal cord
-High-pitched sounds, vocal cords taut
-Low-pitched- less taut

Question 17

What creates tension in the vocal cords?

Answer 17

Cricothyroid muscle- contracts, tilts the thyroid anteriorly making the vocal cords more taut

Question 18

What is the innervation of the cricothyroid muscle?

Answer 18

Innervated by external branch of superior laryngeal nerve

Closely related to superior thyroid artery, therefore risk of injury- thyroid surgery

Hoarseness of voice when attempted high pitched sounds