Shs 310: Exam 4

Front 1

5 layers of Vocal folds

Back 1

Cover (loose)
squamous epithelium

superficial lamina propria

intermediate lamina propria


Body (stiffer)
deep lamina propria
muscle

Front 2

Why was the histological discovery of the layers important?

Back 2

two layers vibrate in different phases, creating a mucosal wave

Front 3

Describe a cycle of vocal fold vibration.

Back 3

Vocal folds are adducted and held in position by muscular force, surface tension and gravity

Alveolar pressure is raised by volume compression
Subglottal pressure builds and blows apart vocal folds (bottom to top)

Recoil forces start to bring the vocal folds back together (bottom to top)

Airflow begins to diverge, decreasing pressure, sucking folds back together (related to Bernoulli effect)

Front 4

What is a vertical phase difference?

Why does it exist?

Back 4

Basically the movement of vocal folds.
Bottom “lip” precedes upper “lip” in opening and closing

Phonation

Front 5

Horizontal phase diffference

Back 5

If you were to make a transverse (horizontal) cut just above the vocal folds, you would see that (looking down from the top of the vocal folds) it doesn't open all at once. It opens midline at the cartilagenous portion of the vocal cords and then continues like a zipper to each end. It closes in the same pattern, from the ends to the cartilagenous portion.

Front 6

What is a mucosal wave?

Back 6

"wave-like" movement of the vocal fold cover (epithelium + superficial lamina propria) over the vocal fold body (vocalis muscle).

Front 7

What are the elastic recoil forces at play during vibration?

Back 7

.....

Front 8

Besides phonation, what are 3 life functions that the larynx performs?

Back 8

Protect lower airway
Forcefully expel foreign material (cough)
Thoracic fixation