Quiz 1 Flashcards
(19 cards)
What are the five intrinsic laryngeal muscles?
Cricothyroid, Thyroarytenoid, Lateral Cricoarytenoid, Posterior Cricoarytenoid, Ventricular Folds (False VFs).
What are the three critical effects of the intrinsic laryngeal muscles?
Changes position of cart framework that houses VF
Alters length tension and shape of VF edge
Changes the shape of the glottal opening between VF
What are the functions of the intrinsic laryngeal muscles?
Acronym FLTET (fucking let this end tonight)
abuduction or adduction of the VF
Shortening or lengthing of the VF
Thickening or thinning of the VF body
Sharpening or rounding of the VF fold free edge
Increasing or decreasing stiffness of the VF
Larynx
a cartilaginous tube that connects inferiorly to the respi- ratory system, (trachea and lungs), and superiorly to the vocal tract and oral cavity.
3 subsystems of speech
pulmonary power supply (respiration
laryngeal valve (phonation)
supraglottic vocal tract resonator (resonance)
Lungs
function as the power supply by providing aerodynamic tracheal pressure blowing the vocal folds apart and into vibration
Oscillation
vibration from vocal folds that provides the sound source for phonation
Differential Diagnoses
laryngeal health, vocal function, respiratory support, and supraglottic resonance affect speech product
Three basic functions of the larynx
airway preservation (opening) for ventilation, airway protection (closing) to block or repel environmental infiltrates, and phonation (vocal fold vibration) for communication and sing- ing.
Three levels of folds:
Aryepiglottic folds:
Ventricular folds (aka false folds)
True vocal folds:
LARYNGEAL REFLEXES
preserves the airway through a series of sensory receptors that have the ability to elicit tight sphincteric closure to close off the trachea and lungs to protect the airway from foreign materials or aspira- tion.
DEVELOPMENTAL CHANGES
larynx is high in the neck in newborns, then descends as the baby grows until puberty, when the larynx is at its lowest point
VF length is the same for both genders until age 10
By adulthood, the female overall VF length is 11 to 15 mm, whereas the male length is 17 to 21 mm
GERIATRIC VOCAL FOLDS
VFs thin with age (bowed)
presbylaryngeus = geriatric changes in voice quality and laryngeal appearance
two important processes present in the aging thyroarytenoid muscle
a proliferation of myonuclei and associated satellite cells that accompany a specialized process called apoptosis, or planned cell death (suicide) which results in loss of type 1 muscle fibers in the VFs
aging thyroarytenoid muscle tissues exhibit proportional increases in the developmental myosin isoform, which is only present in adults when muscle fibers are regenerating, suggesting that the human vocal fold muscle fibers retain the ability to partially compensate for these tissue changes by spontaneously regenerating with age
Van den Berg’s Aerodynamic-Myoelastic Theory
airflow (aerodynamic) and muscular (myoelastic) properties account for the motions of the VFs during phonation
pressure rises, blowing apart the VFs, pressure lowers, increasing the rate of air through the glottis, which draws the VFs back together (adduction)
Oscillation is a function of two contributions: covarying pressure and flow and the mechanical properties of tissue deformation and collision.
Hirano’s Body-Cover Theory
role of passive (non-muscular) superficial layers (epithelium and lamina propria) to vocal fold vibration
accounts for the mass and stability provided by the vocalis muscle and deep layer of the lamina propria, over which the compliant and flexible layers of the lamina propria and epithelium oscillate
3 vibratory phases of wave motion
Horizontal (medial to lateral move- ments), as seen during the open and closing patterns of vibration
Longitudinal (anterior to posterior “zipperlike” wave), as seen in a front- to-back traveling wave
Vertical phase (inferior to superior opening and closing of the vocal folds), seen as an upper versus lower lip difference in some views of vocal fold vibration.
Titze’s Self-Oscillation Theory
describes the vocal folds as a flow-induced self-oscillating system, sustained across time by the aerodynamic forces of pressure and flow
respiration is the driving force that sets the vocal folds in motion (oscillation) and the interchange between pressure and flow at three critical sites keeps the vocal folds vibrating:
subglottal region, intraglottal space, supraglottal air column
FUNDAMENTAL FREQUENCY
Fundamental frequency is the rate of vocal fold vibration, usually expressed in cycles per second, or hertz
factors that determine fundamental frequency control are vocal fold length and tension, including passive tension on the vocal fold cover and active stiffness of the vocal fold body
higher pitch = cricothyroid contracts
lower pitch = thyroarytenoid contracts
subglottal pressure increases proportionally with increased fundamental frequency in the midrange
vibratory amplitude motion is inversely proportional to the rate of vocal fold vibration
PHONATION MODES AND VOICE QUALITY CONTROL
phonatory quality is affected by the integrity of vocal fold vibration, as defined by regularity, symmetry, phase shape of tissue deformation, and the slope of the glottal flow waveform
Deviations will impair the resulting acoustic signal.
the quality of voice relies on multiple factors, including compliant and symmetric biomechanic properties of the vocal folds, an adequate and consistent subglottic pres- sure and flow source, and appropriate vocal tract tuning characteristics.
three special phonation modes, or registers:
Falsetto (loft), modal (chest) voice, glottal fry (pulse)
