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Supraglottic Glottic Subglottic. Vegitative function Voiced/Voiceless 5 layers of tissue.
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Supraglottic Glottic Subglottic • Vegitative function • Voiced/Voiceless • 5 layers of tissue
Aerodynamic Myoelastic Theory: vibration of the vocal folds is the product of air flow and pressure through a constricted tube interacting with the elastic component of muscle tissue in absence of repetitive muscular contraction Bernoulli Principle: given a constant volume flow of air or fluid, at a point of constriction there will be decrease in air pressure perpendicular to the flow and an increase in velocity of the flow
Phases: Opening Open Closing Closed One Vocal Fold Cycle Sustained Phonation: The interaction of subglottal pressure, tissue elasticity, and constriction as long as pressure flow and vocal fold approximation are maintained
Cartilages of the Larynx Cuneiform Cartilage Structures connected by intrinsic ligaments and membranes
Fibroelastic Membrane Upper quadrangular membranes Aryepiglottic folds Lower conus elasticus Vocal ligament
Valleculae:a valley found between the base of the tongue and epiglottis within folds arising from the glossoepiglottic ligaments Pyriform Sinus: valley lateral to the vocal folds
Cover: 1,2,3 Body: 4,5 Mucosal Lining: 1,2 Vocal Ligament: 3,4 Muscle: 5 5 Layers of Tissue: Squamous cell epithelium 1 Lamina propria elastin fibers-random 2 elastin fibers-ap 3 collagen fibers-ap 4 Thyrovocalis muscle 5
Spaces • Aditus:entry to the larynx from the pharynx above, entryway to the first cavity • Vestibule: first cavity of the larynx, between aditus and ventricular/vestibular folds • Laryngeal ventricle: space between the ventricular folds and vocal folds • Glottis: space between the vocal folds
The arytenoid cartilages sit on the superior surface of the cricoid. The cricoarytenoid joint permits rotation, rocking, and gliding.
Hyoid Bone: Only bone in the body that is not attached to other bone Supra hyoid: laryngeal elevators Infra hyoid: laryngeal depressors
Cricothyroid Joint: contraction of the cricothyroid muscle, the effect is to tense the vocal folds
Articular facet of the arytenoid cartilage permits inward rocking, ap gliding, and rotation.
Intrinsic Laryngeal Muscles Adductors Innervation: Recurrent Branch of X Vagus • LCA: draws muscular process forward, this rocks the arytenoids inward and downward creating adduction • TA: pulls the arytenoids together approximating VF, important in medial compression (degree of force applied by the vocal folds at their point of contact) • OA: pulls apex of arytenoid medially which promotes adduction, enforces medial compression, rocks arytenoids down and in, aids in pulling the epiglottis over the larynx, serves tight adduction
Intrinsic Laryngeal Muscles Abductor Innervation: Recurrent Branch of X Vagus • PCA: pulls muscular process posteriorly, abducts vocal folds, direct antagonist to LCA
Glottal Tensors • CT: rocks the thyroid cartilage downward (pars recta) and forward (pars oblique) thus stretching or tensing the vocal folds, this is the major adjustment for pitch change Inn. Superior Branch of X Vagus • ThyV: medial muscle of vocal folds, tenses vocal folds in its activity as antagonist to CT Inn. Recurrent Branch of Vagus
Intrinsic Laryngeal Muscles Relaxers Innervation: Recurrent Branch of X Vagus • ThyM: may be considered part of ThyA, lateral to TV • Lateral fibers of TM adduct and lengthen VF • Medial fibers relax VF • Sup ThyA: Some consider part of TM • - Relaxes VF
Interaryteniod Muscles Posterior Cricoarytenoid Muscles
Abduction and Adduction
Vocal Fold Contraction Movement due to the Cricothyroid M.
Extrinsic Laryngeal Muscles Supra Hyoid Laryngeal Elevators
Supra Hyoid Laryngeal Elevators • Digastric: elevate the hyoid, can pull mandible inferiorly if infrahyoids are fixed • Anterior: draw the hyoid up and forward, Inn. V Trigeminal • Posterior: draw the hyoid up and back, Inn. V11 Facial • Stylohyoid: elevates and retracts hyoid bone, with anchoring of infrahyoids could facilitate tongue movement Inn. V11 Facial
Supra Hyoid Laryngeal Elevators • Mylohyoid: forms the floor or the oral cavity, elevates hyoid and projects it forward, elevation of the floor of the mouth during the first stage of deglutition, depress mandible with IH fixed Inn. V Trigeminal • Geniohyoid: superior to mylohyoid, elevates hyoid, draws it forward, depress mandible with IHfixed Inn. XII Hypoglossal
Supra Hyoid Laryngeal Elevators • Hyoglossus: lingual depressor or hyoid elevator Inn. XII hypoglossal • Genioglossus: muscle of the tongue which will elevate the hyoid Inn. XII Hypoglossal • Thyropharyngeus: part of inferior constrictor m., propels food through the pharynx, elevates larynx and constricts pharynx, not a SH m. Inn. ansa cervicalis arising from C1-C3 spinal nerves
Extrinsic Laryngeal Muscles Infra Hyoid Laryngeal Depressors
Infra Hyoid Laryngeal Depressors • Sternohyoid: depress hyoid, lowering important following pharyngeal stage of swallow, with SH m. are contracted it will fix hyoid and larynx Inn. ansa cervicallis C1-C3 • Omohyoid: two bellies scapula to hyoid, depress hyoid and larynx Inn. ansa cervicalis C1 (sup) C2 and C3 (inf)
Infra Hyoid Laryngeal Depressors • Sternothyroid: depress thyroid cartilage, draws larynx inferiorly following pharyngeal stage of swallow Inn. spinal nerves from C1 and C2 that course in the hypoglossal nerves • Thyrohyoid: superior counterpart of sternothyroid, either depress hyoid or raise larynx depending on who is fixed Inn. spinal nerves from C1 that course in hypoglossal nerve
Oscillation: continued vibration Elasticity: return to original shape after being displaced Stiffness: strength of the forces held within a given material that restores it to its original shape after being distended Inertia: property of mass that dictates that a body in motion tends to stay in motion Periodic: repeats itself in a predictable fashion Cycle of Vibration: moving from one point in the vibratory pattern to the same point Period: the time it takes to pass through one cycle of vibration
Frequency: how often something occurs, how often a cycle of vibration repeats itself, frequency equals 1 divided by the time it takes for one period f=1/T: T=1/f Frequency is measured in Hertz (Hz) which is the numbers of cycles per second
Vocal Fundamental Frequency • The primary frequency of vibration: Fo 100Hz • Harmonics (Ho) are multiples of this Fo 200,300,400,500HZ • Formant Frequencies are vocal tract resonances, do not relate to the Fo or Ho 400HzF1 2600HzF2
Vocal Intensity • Relative power or pressure of an acoustic signal • Direct function of the amount of pressure exerted by the sound wave • Measured in decibles (dB)
Vegitative Function Cough Throat Clearing Swallow Abdominal Fixation Laryngeal Postures
Vocal Attack • Attack: the process of bringing vocal folds together to begin phonation • Simultaneous vocal attack: coordinate adduction and onset of respiration • Breathy Vocal Attack: starting significant air flow before adducting the vocal folds • Glottal Attack: adduction of the vocal folds occurs prior to air flow, hard glottal attack may damage vocal tissues
Vocal Register: differences in mode of vibration of vocal folds Register/Mode • Mode of Vibration: pattern of activity that the vocal folds undergo during a cycle of vibration, varies for each register • VF variation dependent on laryngeal tension, medial compression subglottal pressure
Registers • Modal: the pattern of phonation used in daily conversation • Pressed: medial compression is greatly increased, strident or harsh quality, vocal abuse • Breathy : inadaquate closure in closed phase, inefficient with air wastage
Registers • Glottal Fry: different or syncopated vibration in low frequency, rough perceptually, low subglottal pressure, reduced vocalis tension, vibrating margin flaccid and thick, strong medial compression due to lateral portion of vocal fold is tensed, long closed cycle • Falcetto: elevated pitch, breathy, vocal folds lengthen and are thin, glottis remains open, no closed cycle
Whispering • Not a phonatory mode • VF partially adducted and tense • Produces turbulent air stream • Enlarged space in cartilagenous larynx • Breathy vs tense whisper
Vetricle Transverse Transverse Phase: less consistent, opening posterior to anterior, closing posterior is last Verticle and Transverse Phase Relationships During One Glottic Cycle Verticle Phase:opening and closing is inferior to superior
Frequency, Pitch, Pitch Change • Pitch • Perceptual correlate of frequency • Important element in speech perception • Change is perceived when mass of VF and elastic elements change • Increase by stretching and tensing VF using cricothyroid and vocalis m.
Frequency, Pitch, Pitch Change • Optimal Pitch • Most appropriate for an individual • Function of mass and elasticity of VF • About ¼ octave above the lowest frequency of vibration • Function of gender and age
Frequency, Pitch, Pitch Change • Habitual Pitch: frequency of vibration of the vocal folds habitually used during speech, ideally same as optimal pitch • Average Fundamental Frequency: frequency of vibration of sustained phonation, best determined in a conversational sample • Pitch Range: individual Fo range calculated as difference between lowest and highest frequencies averages around 2 octaves
Tension, Length, Mass of VF • Tension increased by contraction of the CT and TV, will increase Fo vibration • Mass per unit length is decreased by lengthening the VF, as mass decreases Fo increases • Mass per unit length increases, tension decreases and Fo decreases • Increased Fo requires increased tension which requires increased subglottic pressure
Intensity and Intensity Change Intensity (SPL): physical measure of power or pressure ratios Loudness: perceptual correlate of intensity, how we perceive pressure or power changes Subglottal Pressure: increased to increase vocal intensity Medial Compression: increased to increase vocal intensity
Impedance Measurements on EGG Longer Closed Phase = Increased Intensity = Increased VF tension, Mass, and Subglottal Pressure Conversation Level Sustained Vowel Loud Sustained Vowel