Exam 2: Phonation II

Question 1

Interarytenoid Muscles

Answer 1

• Adductors
• located on the posterior surfaces of the arytenoid cartilages
• Described as oblique and transverse arytenoid muscles

Question 2

Oblique arytenoid muscle characteristics

Answer 2

• more superficial
• looks like an X
• a few muscle fibers continue around the apex of the arytenoid cartilage laterally, angle upward and forward, and insert into the lateral borders of the epiglottis as the aryepiglottic muscle

Question 3

Oblique Arytenoid: Origin & Insertion, function

Answer 3

Origin: posterior surface of the muscular process and adjacent posterlateral surface of one aryenoid cartilage

Insertion: near the apex of the opposite cartilage

Function: approximate the arytenoid cartilages and are therefore regulators of medial compression

Question 4

Transverse Arytenoid Muscle: Origin & Insertion, function

Answer 4

Origin: from the lateral margin and posterior surface of one arytenoid cartilage, course in a horizontal direction

Insertion: lateral margin and posterior surface of the opposite arytenoid cartilage

Function: contraction approximates the arytenoid cartilage by causing them to slide along the long axis toward the midline

Question 5

Cricothyroid Muscle characteristics

Answer 5

• tensor
• actively tense or elongate the VF
• only other tensor (than thyroarytenoid muscle)
• fan-shaped

oblique fibers– pars oblique
anterior fibers– pars recta

Question 6

Cricothyroid Muscle: Origin & Insertion

Answer 6

Origin: anterolateral arch of the cricoid cartilage

diverges and

Insertion: the thyroid cartilage as two distinct parts

Question 7

Pars Oblique

Answer 7

lower fibers course upward and back to inset into the anterior margin of the inferior horn of the thyroid cartilage

Question 8

Pars Recta

Answer 8

upper or anterior fibers course nearly vertical upward to insert along the inner aspect of the lower margin of the thyroid

Question 9

2 parts of the arytenoid muscle

Answer 9

oblique and transverse

Question 10

5 distinct layers of the VF

Answer 10

1. Epithelium (cover)
2. superficial layer of the lamina propria (cover)
3. Intermediate layer of the lamina propria (transition)
4. Deep layer of the lamina propria (transition)
5. vocalis muscle (body)

Question 11

Epithelium of VF

Answer 11

made of: squamous epithelium

• thin and stiff capsule
• maintains shape of the vocal fold (like a capsule would)
• helps regulate VF hydration

Question 12

Superficial layer of the lamina propria

Answer 12

• Reinke’s space
• consists of loose fibrous components and elastic components in a matrix
• mass of soft gelatin

Question 13

Intermediate layer of the lamina propria

Answer 13

made of: elastic fibers

• likened to a bundle of soft rubber-bands
• composed mostly of elastic fibers

Question 14

Deep layer of VF

Answer 14

made of: collagenous fibers

• like a bundle of cotton threads
• made up of collagenous fibers, contributes to durability of VF

Question 15

Vocalis Muscle in VF

Answer 15

• has both passive and active mechanical properties
• constitutes the main body of the VF
• passively, is like a bundle of stiff rubberbands
• it is a muscle, so it is active (contractile properties, help control stiffness)

Question 16

Thyroarytenoid Muslce (TA)

Answer 16

• main mass of the VF
• vocalis muscle (medial bundle) flanks the vocal ligament
• thyromuscularis (lateral bundle) serves as the “body” of the muscle

Question 17

Vocal Fold’s 3 sections

Answer 17

1. the cover (epithelium and superficial layer of lamina propria), aslo called mucosa
2. transition (intermediate and deep layers of lamina propria; this is the vocal ligament
3. Body (vocalis muscle)

Question 18

Physiology of VF (Thyroarytenoid)

Answer 18

• the mechanical properties of the outer four layers are controlled passively
• mechanical properties of the body are regulated both passively and actively
• during phonation, a wave traveling on the laryngeal mucosa from its inferior to superior surface can be seen during each cycle of vocal fold vibration, except when the vocal fold is very tense (ex: falsetto)

Question 19

Mucosal Wave

Answer 19

• soft & pliant superficial layer of the lamina propria is essential for the mucosal wave
• this wave continues across the upper surface of the vocal fold, dissipates before it arrives at the boundary of the thyroid cartilage

Question 20

Principle function of TA muscle

Answer 20

• regulator of longitudinal tension
• acting unopposed by intrinsic muscle, relaxes VF
• assists in closing glottis by pulling forward on the muscular process
• when contraction of TA is opposed by intrinsic muscle, the result is an increase in VF tension, then can act as adductor, a tensor or a relaxer of VF

Question 21

Pre-phonation phase

Answer 21

period during which the VF move from an abducted to either an adducted or partially adducted position

quiet breathing prior to phonation

Question 22

vocal fold approximation

Answer 22

subglottal pressure builds up beneath the vocal folds

the velocity of air as it flows through the glottal contrition is raised sharply

Question 23

Medial Compression

Answer 23

the extent to which the VF are approximated, this is brought about by the action of the adductor muscle

• brought about by adductor muscles
• muscles work in pairs…contraction of one results in contraction of companion muscles
• direct relationship between the extend of medial compression and the magnitude of air pressure required to force the VF apart and initiate phonation

Question 24

Bernoulli Effect

Answer 24

aerodynamic law
-if the volume flow is constant, velocity of flow must increase at an area of constriction, but with a corresponding decrease of pressure at the constriction

• assume the VF are nearly approximated
• air stream released by exhalation
• velocity will be constant until glottal contraction
• velocity will increase as air passes “chink”
• results in negative pressure between the medial edges of the VF
• VF literally sucked toward one another

Question 25

Initiation of Phonation

Answer 25

- as the glottal area reaches critical value, the VF start to vibrate (before approximation) - initial movement results in a decrease in the glottal area - VF undergo many vibrations before thy meet and obstruct the air stream - if subglottal pressure is adequate, medial compression of VF will be overcome and they will be blown apart to release a puff of air into supraglottal area - explosive - immediate short term decrease in subglottal pressure

Question 26

Elastic Tissue + Bernoulli Effect =

Answer 26

Vocal Folds snap back again to midline

Question 27

Simultaneous attack

Answer 27

there is a healthy balance between the respiratory and laryngeal mechanism air stream released just as the vocal folds meet at the midline "zero"...occurs with voiced sounds

Question 28

Breathy attack

Answer 28

air stream is released before the VF adduction is completed -considerable amount of air may be exhaled while folds are being set into periodic vibration "hairy"...occurs throughout long production strings of words

Question 29

Glottal attack

Answer 29

when phonation is initiated while the vocal folds are subjected to considerable medial compression - voice exhibits an onset more than during either simultaneous or breathy attacks - vocal tone is explosive in nature - the initiation is called a glottal attack "okay"...used when words begin with a stressed vowel

Question 30

Attack Phase

Answer 30

begins with the vocal folds adducted, or nearly adducted, extends through the initial vibratory cycles - highly variable in duration - complete obstruction of airway passageway is not necessary to initiate phonation - initial movement in incompletely adducted vocal folds is medial

Question 31

Characteristics of a Vibratory Cycle

Answer 31

- rate of vibration - open vs closed phase - periodicity - symmetry

Question 32

Rate of vibration

Answer 32

- described as frequency (Hz) or cycle per second - very fast - cant' see with blind eye - larynx operates most efficiently at the frequency of vibration that correlates closely with habitual pitch women: 225 Hz kids: 295 (really young)

Question 33

Open vs Closed phase

Answer 33

- VF begin to open first posteriorly - Glottal chick moving anteriorly - Closure begins with the entire medial edge of the folds moving toward the midline - posterior portion is the last to close

Question 34

Conversational Pitch & Intensity

Answer 34

VF vibrate almost in their entirety, vibration is wavelike for the main mass of VF, along horizontal plane, slight vertical displacement that increases with loudness

Question 35

Open Phase

Answer 35

- VF begins to be forced open from beneath - upward progression of the opening in an undulating fashion - lower edges of VF are the first and the upper edges are last to be blown apart

Question 36

Closed phase

Answer 36

the lower edges lead the upper edges (wave-like)

Question 37

Periodicity

Answer 37

- with mass, length, tenstion, and subglottal pressure held constant, vocal fold vibrations will recur with moderately precise regularity - regularity of successive cycle of vibration

Question 38

Symmetry

Answer 38

- VF will open and close as a mirror image of one another | - open and close in synchrony

Question 39

Pitch Nomenclature

Answer 39

- Fundamental frequency - pitch level - pitch ranges - natural level - optimum pitch level

Question 40

Male vs Female VF length

Answer 40

Males: 15-20mm Females: 9-13mm

Question 41

In abducted position, VF are...

Answer 41

near maximum length

Question 42

length of VF at various positions never exceeds...

Answer 42

the length of the vocal folds in their abducted postion

Question 43

Increase in length of vocal chords will...

Answer 43

increase pitch

Question 44

Modifications in length and tention are mediated through...

Answer 44

cricothyroid, thyroarytenoid, and posterior cricoarytenoid

Question 45

Mass in Pitch Changing Mechanism

Answer 45

- high pitch phonation: VF thickness is never reduced to below 1/2 of what it is during lowest pitch phonation - increase in tension in the vocal folds is the sole agent responsible for pitch increases - accompanying length and thickness changes is imply the result of the elastic tissue of the vocal folds yielding to the marked increase in tension