Exam 3 Study Guide Phonatory System PDF

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Study guide for exam 3 on the phonatory system...

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Phonatory System Introduction •

Phonation o A product of vibrating vocal folds o Also known as voicing

Structures of the Phonatory System •

Hyoid Bone o Located at the level of the 3rd cervical vertebrae o Structures ▪ Body (corpus) ▪ Greater cornu • Articulate with the superior horns (cornu) of thyroid cartilage ▪ Lesser cornu • Cone shaped; rise superiorly o Very mobile o Does not connect to any other bone in the body

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Larynx o Function ▪ Protects lower passageway from foreign materials ▪ Can be used to hold air in lungs ▪ Generates sound o Laryngeal Cartilages ▪ Thyroid Cartilage • Largest of the laryngeal cartilages • Articulates inferiorly with cricoid cartilage • Structures o Thyroid laminae ▪ Also called quadrilateral plates o Thyroid angle ▪ Point at which the two thyroid laminae come together o Thyroid notch ▪ Superior-most point of thyroid angle o Thyroid prominence

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▪ “Adam’s Apple” o Cornu ▪ Located on the posterior portion of thyroid ▪ 2 sets • Superior o Points toward hyoid bone • Inferior o Rest on cricoid cartilage Cricoid Cartilage • Most inferior cartilage of larynx • Unpaired, ring-shaped • Structures o Arch ▪ Low narrow portion in front ▪ Provides clearance for the vocal folds o Posterior quadrate lamina ▪ Wide and thick portion in back ▪ Provides point of articulation for arytenoid cartilages Arytenoid Cartilages • Located on superior surface of cricoid cartilage • Allows for rocking, gliding, and rotating o Important for onset and offset of voicing • Structures: Pyramidal shape which includes: o Base o Apex o Vocal Process ▪ Projects anteriorly toward the thyroid notch ▪ Location of the vocal fold attachment o Muscular process ▪ Projects laterally on the arytenoid ▪ Point of attachment for muscles that adduct and abduct the vocal folds s • Small horn-shaped, extension of arytenoids • Support aryepiglottic fold Cuneiform Cartilages • Small cartilages embedded within the aryepiglottic fold • Anterior to corniculate cartilages • Provide support for laryngeal covering Epiglottic Cartilage ( piglot s) • Leaf-like structure

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Stem (petiolus) arises from the inner surface of the thyroid angle, just below notch Attaches by means of the t Protects airway by deflecting food and liquids from being swallowed Epiglottis attaches to the hyoid bone via the hyoepiglottic ligament Surface of epiglottis is covered with a mucous membrane lining

o Laryngeal Joints ▪ Cricothyroid joint • Synovial (diarthroidial) joint that allows the thyroid to tilt downward. This stretches and tenses the vocal folds. • Joint provides the major adjustments for change in vocal pitch ▪ Cricoarytenoid joint • Concave portion of arytenoids articulates with convex portion of cricoid lamina • S ) allows for rocking, gliding, and minimal rotation • Involved in adduction and abduction of vocal folds o L ▪

Extrinsic Laryngeal Membranes and ligaments • Group of ligaments and membranes that connect the cartilages of the larynx to each other and to the hyoid bone and trachea o Thyrohyoid membrane: (Hyothyroid) connects hyoid bone to thyroid cartilage o Hyoepiglottic ligament: connects epiglottis to the hyoid bone o Thyroepiglottic ligament: connects the epiglottis to the thyroid o Cricotracheal membrane: connects the cricoid cartilage to the first tracheal ring

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Intrinsic Laryngeal Membranes and Ligaments • Continuous sheet of connective tissue (elastic membrane)

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Quadrangular Membranes (upper portion) o Aryepiglottic folds ▪ Completely seal off the spaces in the laryngeal structure ▪ Directs the airstream into the ad and upward into the resonatory passageways ▪ First line of defense against foreign objects ▪ Closes during swallowing and vomiting • Prevents food/liquid from entering respiratory tract ntricular folds ▪ Also known as false vocal folds ▪ Pink and plump ▪ Found between laryngeal vestibule and laryngeal ventricle ▪ When the ventricular folds contract, they meet at midline, closing or sealing off the airway ▪ Close during swallowing, and during effortful activities such as lifting heavy objects ▪ During normal phonation, ventricular folds remain in quiet, open position

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Conus Elasticus (lower portion) o Vocal folds ▪ White because of a lack of vascular supply ▪ Third line of defense in keeping foreign objects out of lungs o Cricothyroid ligament ▪ Connects the cricoid cartilage to the thyroid cartilage

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Laryngeal vestibule • Area in larynx above ventricular folds • Opening is called aditus Laryngeal ventricle • Space between vocal folds and ventricular folds Inferior Laryngeal ventricle (subglottal atrium) • Portion below the true folds • Extend through to the trachea

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Valleculae • Area between tongue root and epiglottis • Impaired swallow can cause food/liquid to pool in valleculae which increases risk for aspiration Pyriform sinus • Between the lateral wall of thyroid cartilage and aryepiglotic folds • Impaired swallow can cause food/liquid to pool in pyriform sinus which increases risk for aspiration Glottis • Opening between vocal folds • Triangular shape during quiet respiration • : the anterior-most region of the glottis • : the posterior-most region of the glottis

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Cover • Epithelium o Mucosal covering of stratified squamous cells o Needs a thin layer of mucous lubrication for best oscillation • Superficial lamina propria (also called Reinke’s space) o Extracellular gelatin matrix o Helps cushion the vocal folds Transition/Vocal Ligament • Intermediate lamina propria o Compose of elastic fibers o Part of the vocal ligament • Deep lamina propria o Collagen fibers o Supportive o Part of the vocal ligament Body • Thyroarytenoid o Thyrovocalis + Thyromuscularis o Provides tone, stability and mass

o Laryngeal Musculature ▪ Functions • Regulate valve openings and closings o Epiglottic valve

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o Ventricular fold valve o Vocal fold valve Provide movement of laryngeal cartilages for speech

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s Have both origin and insertion within larynx Make fine adjustments to the vocal mechanism

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dduct – bring together o Lateral cricoarytenoid ▪ Action: Adducts the vocal folds. o Transverse arytenoid (only unpaired intrinsic muscle) ▪ Action: Adducts vocal folds o Oblique arytenoid ▪ Action: adducts vocal folds (how tightly VF are pressed against each other), rocks arytenoid and vocal folds down and inward Abductor – pull apart o Posterior cricoarytenoid ▪ Action: Abducts vocal folds

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s – tighten muscles o Cricothyroid ▪ Primary tensor of the vocal folds ▪ Responsible for laryngeal adjustments associated with pitch change • Recta o Action: Rotates thyroid cartilage downward • Pars Oblique o Action: rotates thyroid cartilage downward, stretches vocal folds o Thyrovocalis (part of thyroarytenoid) ▪ Body of vocal folds ▪ Action: tenses vocal folds

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– relax muscles o Thyromuscularis (part of thyroarytenoid) ▪ Action: Shorten and relax vocal folds

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s One attachment to the larynx and the other attachment on a structure outside the larynx Forms a network that surrounds the larynx and anchors it in position within the neck. Makes major adjustments to larynx o Elevating o Depressing

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Hyoid and Laryngeal Elevators o Digastricus ▪ Anterior • Function: elevates hyoid anteriorly ▪ Posterior • Function: elevates hyoid posteriorly o Stylohyoid muscle ▪ Action: elevates hyoid posteriorly o Mylohyoid muscle ▪ Makes up the floor of oral cavity ▪ Action: elevates hyoid anteriorly o Geniohyoid muscle ▪ Action: elevates hyoid anteriorly o Genioglossus muscle ▪ Forms the primary muscle of the tongue ▪ Action: elevates hyoid o Hyoglossus muscle ▪ Action: elevates hyoid and depresses tongue

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Hyoid and Laryngeal D sors o Sternohyoid muscle ▪ Action: depresses hyoid o Omohyoid muscle (superior and inferior) ▪ Action: depresses hyoid o Sternothyroid muscle ▪ Assist on producing high and low pitch ▪ Helps make fine adjustments to vocal folds ▪ Action: depresses thyroid cartilage o Thyrohyoid muscle ▪ Action: depresses hyoid or elevates larynx

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Vocal Fold Vibration (Vi ration of the vocal folds OT the product of repeat on an duction of the vocal folds) o Myoelastic-Aerodynamic Theory of Phonation ▪ Myoelastic • Elasticity: Returns to original shape after being displaced (Vocal folds are muscles covered by delicate membranes. This soft tissue allows them to move when sufficient force is exerted. • Stiffness: Strength of material that restores it to original shape • Inertia: a body in motion tends to stay in motion ▪ Aerodynamic • Bernoulli’s Principle o There will be an increase in velocity of airflow at a point of constriction o And a decrease in air pressure perpendicular to the flow

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Laryngeal Function o Attack: adduct vocal folds to initiate phonation o Sustain Phonation: maintain laryngeal posture, ongoing airflow maintains the vibration o Termination: abduct vocal folds to stop phonation

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Frequency/Pitch and Amplitude/Loudness o Frequency ▪ Rate of vibration of an object ▪ Measured in cycles per second (Hertz – Hz) o Pitch ▪ Perception of sound’s frequency ▪ Vibration rate related to vocal fold thickness (mass), length, and elasticity (tension) • Higher pitch o Faster the vibration (the higher the frequency) the higher the sounds will be perceived o Contraction of cricothyroid muscles ▪ Lengthens vocal folds and thins medial edge • Lower pitch o Slower the vibration (the lower the frequency) the lower the sound will be perceived o Contraction of thyromuscularis

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Brings thyroid cartilage and arytenoids closer together Shortens vocal fold length, making them more massive and less tense

o Amplitude ▪ Amount of displacement of an object from its rest position ▪ Measured in decibels (dB) o Loudness ▪ Perception of the sound’s amplitude • Increase Loudness o The greater the amplitude the louder is the sound that is heard and vice versa o Increase medial compression of vocal folds ▪ Vocal folds press together more tightly ▪ Vocal folds press together for a longer period of time •

Voice Quality o Normal Voice Quality ▪ Maximum f • The voice is flexible in pitch during conversation ▪ Minimum-maximum amplitude • The voice is able to vary loudness ▪ Maximum p • Measured by the longest period of time that an individual can sustain a vowel on one breath o Adults: 15 – 25 seconds o Children: at least 10 • Coordinated air flow with vocal fold adduction ▪ M nima tive • Minimal breathiness or roughness o Abnormal Voice Qualities ▪ Dysphonia • Generic term for any voice that sounds deviant in terms of quality, pitch, and or loudness • Breathiness o Vocal folds don’t close completely during each vibratory cycle o Air leakage at the glottis creates a friction noise o Breathy noise is measured at the higher frequencies • Rough/Hoarse Voice o Excessive vocal fold closure during phonation

o Vocal folds vibrate in a less periodic cycle o Rough/Hoarse noise is measured at the lower frequencies •

Acoustic Analysis o Praat ▪ Advantages • Easily accessible • Inexpensive • Safe and non-invasive • Provides quantifiable data ▪ Disadvantages • Different calculation algorithms for different programs • Not useful for severely dysphonic voices • Validity and reliability issues (placement and quality of microphone, background noise, acoustics in the room) o

Perturbation Measurement ▪ Jitter • Frequency perturbation ( ing variability between cycles of vib tion) • Normal jitter values: 0.2% to 1% ▪ Shimmer • Amplitude perturbation (amplitude variability between cycles) • Normal shimmer values: below 0.5 dB

o Noise Measures ▪ Harmonic to noise ratio • Measures the amount of additive noise in the voice • Lower than normal harmonic to noise ratio: suspect problems with vocal fold vibration/adduction •

Vocal Fold Disorders o Laryngitis ▪ Inflammation of the vocal folds ▪ Caused by excessive use of the voice, infections, inhaled irritants, or reflux o Vocal nodules ▪ Noncancerous growths on the vocal cords, similar to a callus ▪ Most often caused by vocal abuse o Vocal polyps ▪ Soft noncancerous growth, similar to a blister o Vocal fold paralysis ▪ One or both vocal folds doesn’t open or close

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Caused by injury, problems in surgery, stroke, cancer, neurological disorders

Facilitative and Aversive Activities of the Vocal Folds o Whisper ▪ Relaxed whisper • Less stressful to vocal folds • More open and softer ▪ Forced whisper • Strong, funneled air stream • Stiffened folds • Turbulence just above glottis o Yawning ▪ Facilitates relaxation of vocal tract musculature o Coughing ▪ Airway protection ▪ Encourage adduction of vocal folds ▪ Prolonged cough abusive to vocal folds o Throat Clearing (vocal folds grate on each other) ▪ Can help remove irritants ▪ Entire larynx goes into stressful movements • Encourage very soft and breathy clearing • Loud or frequent – abusive to vocal folds o Laughing ▪ Laryngeal musculature are reflexively relaxed ▪ Can help generate efficient vocal physiology in voice therapy ▪ Can cause excessive laryngeal pressure and stress if done too loudly or excessively o Crying ▪ Open, relaxed cry • Enriched resonance between the vocal folds and the supraglottic resonating spaces ▪ Tight, loud, or excessive crying • Laryngeal and supraglottic musculature are tensed...