SLP 542 Week 2 Quiz - Quizizz

posterior cricoarytenoid (PCA)

• Only abductor

• Originates on the posterior surface of the cricoid (the large signet ring portion) and inserts on the muscular process of the arytenoids

• Rotates the arytenoids medially to abduct TVFs

Bernoulli effect

• Theory of phonation/ vibration - breath from the lungs (subglottal pressure) pushes the vocal folds apart.

• POSTIVE pressure between the true vocal folds causes the TVFs to be pulled back together from bottom to top, then pushed apart again by subglottal pressure from lungs

cricothyroid muscle

• connects the cricoid cartilage and the thyroid cartilage

• when contracted, it rocks the thyroid forward and down on the cricoid

• movement tenses/stretches the TVFs, resulting in tension in the thyrovocalis

• more tension in the vibrating edge of the TVFs = higher pitch

attachment of the TVFs

• thyroid prominence / thyroid notch = anterior commissure (anterior attachment)

• vocal processes of the arytenoid = posterior commissure (posterior attachment)

layers of the TVFs

5 layers:

• epithelium

• superficial layer of the lamina propria (SLLP)

• intermediate layer of the lamina propria (ILLP)

• deep layer of the lamina propria (DLLP)

• vocalis (TA)

outer layers of TVFs

more elastin fibers and less organization of fibers

inner layers of TVFs

more collagen fibers and are more dense/organized

lateral cricoarytenoid (LCA)

• adductor

• starts on the upper border of the anterolateral arch of the cricoid (front-side edge of the cricoid) and attaches to the muscular process of the arytenoid

• contraction rotates the arytenoid 30 degrees medially to bring TVFs together (adduction)

ossification

• aging process where cartilage is replaced by bone

• more frequently seen on the thyroid vs the cricoid

interarytenoids

• adductors

• 2 sets

  • oblique fibers

  • transverse fibers

suprahyoid muscles

• laryngeal elevators

• anterior belly of the digastric

• geniohyoid

• mylohyoid

• posterior belly of the digastric

• stylohyoid

infrahyoid muscles

• laryngeal depressors

• sternohyoid

• sternothyroid

• omohyoid

• thyrohyoid

recurrent laryngeal nerve (RLN)

• supplies motor function to all intrinsic muscles except the cricothyroid (CT)

• responsible for adduction/ abduction

• ipsilateral innervation

• supplies sensory function to subglottal tissue

• right and left side course down into thoracic cavity

• left RLN is more susceptible to injury during surgeries

vocal fold body

vocalis muscle (thyrovocalis segment of the TA)

superior laryngeal nerve (SLN)

• primary sensory nerve of the larynx

• 2 branches

  • internal branch

  • external branch

internal branch of SLN

sensory for mucosa of epiglottis, TVFs, FVFs, arytenoid region

external branch of SLN

motor for CT muscle

intrinsic laryngeal muscles

5 paired muscles

• thyroarytenoid (thyrovocalis/thyromuscularis)

• posterior cricoarytenoid

• lateral cricoarytenoid

• transverse arytenoid/ interarytenoids

• oblique arytenoids/ interarytenoids

intrinsic laryngeal muscles function

Responsible for movements of the laryngeal cartilages for abduction/ adduction, laryngeal tension, and the size/ shape of the glottic space

vocal fold ligament

• intermediate and deep layers of the lamina propria

• combo of elastin and collagen fibers that are more organized

• allows for vibrations ranging from 80-1100 H

glottis

the space between the true vocal folds - changes as a result of vocal fold vibration/phonation

myoelastic theory of voice production

• subglottal air pressure develops until it is strong enough to separate the bottom edge of the TVFs

• once the edges separate, inertia and the elasticity of the TVF tissues combine with the changes in air pressure to maintain phonation/ vibration

thyroid cartilage

• sits on top of the cricoid cartilage

• has the ability to rock forward and down

• houses the true vocal folds

epiglottis

• elastic cartilage

• provides glottic closure during swallowing

• no significant role in voice production

male anatomy

• thyroid prominence is larger (bc the angle is smaller)

• TVFs are thicker and have more mass (causing a lower fundamental frequency)

female anatomy

• thyroid prominence is smaller in females bc of a wider angle

• TVFs are narrower and have less mass

relaxation

• decreased stiffness of the true vocal folds

• associated with greater activation of the thyroarytenoid muscle (lowering pitch)

tension

• increased vocal fold length and stiffness

• increased tension associated w cricothryoid activation and elevated pitch

mechanisms to change loudness

• increased subglottal pressure

  • increases peak flow rate and vibratory amplitude (lateral excursion) of the TVFs

vocal fold cover

epithelium + superficial layer of the lamina propria

vocal process

• posterior attachment point of the thyrovocalis / TVFs

thyrovocalis or vocalis muscle

bulk of the TVF (thyroarytenoid) muscle

arytenoid cartilage

• paired cartilages that connect to the cricoid cartilage via the cricoarytenoid joing

• rotate inward/medially ~ 30 degrees for TVF adduction and then laterally to resting position for TVFs abduction

• 2 attachment points

• vocal process: posterior attachment point of the thyrovocalis / TVFs

• muscular process: posterior attachment point of the lateral cricoarytenoid (adductor) and posterior aricoarytenoid (abductor) muscles

cricoid cartilage

• Unpaired cartilage that forms the inferior base of the larynx

• Shaped like a signet ring with a broad posterior face and thinner arch (the "ring band") anteriorly

• Attaches to thyroid cartilage via inferior horn of the thyroid

• Attaches to the first tracheal ring via cricotracheal ligament

cranial nerve 10

• vagus nerve

• mixed nerve

• longest cranial nerve

• 3 branches

  • pharyngeal

  • recurrent laryngea

  • superior laryngeal

extrinsic laryngeal muscle function

Suspend the larynx in a muscular sling and connect it to the hydoid bone

Responsible for larger laryngeal movements

Laryngeal elevation - primarily during swallowing and singing (e.g., belting)

Laryngeal depression - primarily during singing and inspiration

extrinsic laryngeal muscle anatomy

5 Laryngeal elevators (Suprahyoid muscles) and 4 Laryngeal depressors (Infrahyoid muscles)

thyroarytenoid

• Forms the body of the TVF

• Shortens the TVF when contracted

• Has 2 sections - thyrovocalis (tenses the vibrating edge) and thyromuscularis (relaxes the vibrating edge)

laryngeal prominence/ thyroid prominence/ anterior commissure

attachment point of the TVF

phonation threshold pressure (PTP)

minimum pressure needed to sustain TVF vibration

mechanism for pitch change

Changes in TVF length changes the tension/stiffness of the TVF cover (higher pitches - more tension/stiffness, lower pitches - less tension/stiffness)

Increased subglottal pressure can increase fundamental frequency by increasing the lateral excursion/ vibratory amplitude of the TVF

oblique fibers of interarytenoids

originates on the posterolateral artynoid - bottom side - and insert diagonally on tip of opposite arytenoid to form an X

transverse fibers of interarytenoids

run horizontally from the posterolateral surface of one arytenoid to the posterolateral surface of the opposite arytenoid