Anatomy & Physiology Exam 2
Glottis
(opening between the vocal folds) is bounded in the front by the membranous vocal folds and in the back by the vocal processes of the arytenoid cartilages
lateral cricothyroid membranes (intrinsic)
(two) thinner than the middle cricothyroid ligament and extend upward from the upper border of the anterior arch of the cricoid cartilage at the side. They, like the middle cricothyroid ligament, restrict the separation of the cricoid and thyroid cartilages toward the front. The lateral cricothyroid membranes thicken significantly toward the top of the conus elasticus and are continuous with the paired vocal ligaments.
hard vocal attack (glottal attack)
-expiration occurs after adduction of the vocal folds -adduction of the folds occurs prior to the airflow
breath vocal attack
-expiration occurs before the onset of vocal fold adduction -significant airflow begins before adducting the vocal folds -causes a breathy voice
Vocal ligaments of the larynx (intrinsic) true v. false vocal cords
-vocal folds (true vocal cords): act in sound production -vestibular folds (false vocal cords): no role in sound production
oblique line of thyroid cartilage
A curving vertical ridge running from the top to the bottom of the posterior external surface of each of the two laminae composing the thyroid cartilage.
State the typical range of vocal intensity (SPL) that can be produced by a young adult.
A vowel produced in a sentence at routine conversational loudness may have an SPL of approximately 65 dB. During a sentence in a routine conversation, vocal intensity (SPL) may vary by as much as 25-30dB.
shortening of vocal folds
Active vocal fold shortening is accomplished primarily by contraction of the thyroarytenoid muscles
Describe the changes in laryngeal structure that occur from infancy through old age.
After age 50, males' F0 increases females' F0 decreases
Larynx function
Airway protection Speech Phonation F0 control Intensity Quality Consonant voicing
abduction of vocal folds
Arytenoid cartilages move outward, upward and backward lengthening the vocal folds
intensity roll-off
As frequency increases across the harmonics, intensity or amplitude decreases by 6 to 12 dB. This relationship of the amplitude decreasing as frequency increases gives the glottal spectrum it's tilted appearance. progressive reduction in relative amplitude with increasing frequency greatly limits the significance of very high frequency harmonics
Vocal intensity
As intensity increases, slope of closure gets steeper As intensity increases, the closed phase of the glottal cycle increases (portion of cycle when vocal folds are closed) Maximum glottal area is constant across intensities
conus elasticus (intrinsic)
Connects thyroid, cricoid, and arytenoid cartilages Cone-shaped membrane extending from vocal folds to inferior border of cricoid
Thyroarytenoid muscle (Thyromuscularis) (intrinsic)
Contraction of longitudinal fibers reduces distance between thyroid and arytenoid cartilages to shorten the vocal folds and/or increases their internal tension
fundamental frequency (F0) during running speech
F0 may vary by as much as two octaves.
ratio of open to closed phases
For each cycle in a typical g waveform, the vocal folds are open about 60% of the time, and closed about 40% of the time. A waveform with a shallower (slower) closing phase is also likely to have more open time throughout a complete cycle. Similarly, a waveform with a steeper (faster) closing phase is likely to have less open time and, therefore, a longer closed phase throughout a complete cycle. Because the speed of closing is often correlated with the open time or closed time (faster speed of closing=less open time; slower speed of closing=more open time), less open time is generally associated with a less tilted glottal spectrum, and more open time with a more tilted glottal spectrum.
Aerodynamic Myoelastic Theory of Phonation
Glottal vibration is the result of an interaction between aerodynamic forces and vocal fold muscular forces
Interarytenoids - intrinsic
Has two parts: transverse arytenoid and oblique arytenoid
infrayoid muscles (extrinsic)
Infrahyoid = originates below the hyoid bone
State the approximate mean F0 for adult male and female speakers.
Male: 125Hz Female: 210Hz
Laryngeal structure and function differences with respect to age and sex
Males have lower fundamental frequencies than females after puberty Fundamental frequency is related to vocal fold mass which is related to overall size (mostly height) and angle of the thyroid cartilage (sharper angle in males) Children generally have higher fundamental frequencies than both men and women
loft register (falsetto)
Occurs in the upper frequency range Results from both the manner and rate of vocal fold vibration Considerable overlap between falsetto and modal Folds vibrate in a shutter-like way Folds are long, thin, and stiff Likely that increased medial compression and longitudinal tension causes the vibratory portion of the folds to reduce, thus causing increase f0. Falsetto Setting: Lower falsetto range - likely result of longitudinal tension Higher frequencies, result of increased medial compression
Digastricus (anterior belly) (extrinsic)
Origin: Inner surface of mandible at digastricus fossa, near the symphysis Insertion: Intermediate tendon to juncture of hyoid corpus and greater cornu Innervation: Mandibular branch of V trigeminal nerve via the mylohyoid branch of the inferior alveolar nerve Action: Pulls hyoid forward; depresses the mandible if in conjunction with anterior digastricus
Mylohyoid (extrinsic)
Originates along the inner surface of the body of the mandible and inserts into a tendinous midline raphe or the front surface of the hyoid bone Course inward, backward, downward Innervated by the inferior alveolar nerve, which stems from the mandibular nerve Contraction pulls upward and forward on the hyoid bone, can also result in elevation of the floor of the oral cavity, tongue, and lower mandible
Thyroarytenoid (paired) (intrinsic) Origin, insertion, fiber course, innervation, action
Originates from inside surface of thyroid cartilage and inserts on ipsilateral arytenoid cartilage, fiber course: parallel to the vocal ligament, innervation: inferior laryngeal nerve, action: relaxes vocal ligament by shortening the distance between the arytenoids and the thyroid. Shortening the distance involves rocking the arytenoids towards the midline. Makes up bulk of vocal folds Consists of the thyrovocalis and thyromuscularis
Stylohyoid (extrinsic)
Originates from the back and side surfaces of the styloid process of the temporal bone and inserts into the body and greater cornu of the hyoid bone Courses downward and forward Innervated by thylohyoid branch of the facial nerve (Cranial Nerve 7) Contraction pulls upward and backward on the hyoid bone
Sternohyoid (extrinsic)
Originates from the back surface of the top of the sternum and inner end of the clavicle and inserts on the lower edge of the body of the hyoid bone fiber course: vertically Contraction pulls downward on hyoid bone
Sternothyroid (extrinsic)
Originates from the back surface of the top of the sternum and the first costal cartilage and inserts on the outer surface of the thyroid cartilage fiber course: upward and slightly to the side Contraction pulls the thyroid cartilage downward, sometimes enlarges the pharynx by pulling the larynx forward and downward
Geniohyoid (extrinsic)
Originates from the inner surface of the front of the mandible to the front surface of the body of the hyoid bone Courses backwards and downwards in a diverging pattern (runs essentially parallel to the anterior belly of the digastic muscle) Contraction can pull upward and forward on the hyoid bone, depresses the mandible
Thyrohyoid (Extrinsic)
Originates in the outer surface of the thyroid cartilage and inserts on lower end of the greater cornu of the hyoid bone fiber course: vertically Contraction decreases the distance between the thyroid cartilage and hyoid bone, which helps to elevate the larynx
Arytenoid cartilages
Pyramid-like cartilaginous structures that form the posterior attachment of the vocal cords.
glottal area function
Shows a graph of the change in glottal area as a function of time during voice production.
Pulse (glottal fry)
Sounds like bacon "frying" Lower limit of pitch range Folds are approximated Folds are flaccid/loose Produced with minimal Ps Frequency range ~ 30 - 80 Hz Closed phase occupies most of the cycle closed ~ 90% of cycle opening and closing ~ 10% of cycle Double pulsing sometimes seen Cricothyroid and vocalis muscle must be relaxed to allow the folds to be loose
Layers of the vocal folds (intrinsic)
Subgroupings of the five layers of the vocal folds into the body and the cover. The body of the vocal folds consists of the muscle and deep layer of the lamina propria (LP) and the cover consists of the intermediate and superficial layers of the lamina propria and the epithelium.
Larynx definition
The area of the throat containing the vocal cords and used for breathing, swallowing, and talking. Also called voice box.
laryngeal aditus (laryngeal cavity)
The laryngeal cavity extends from a lower opening formed by the base of the cricoid cartilage to an upper opening designated as the laryngeal aditus. forms a collar at the top of the larynx.
movement of cricothyroid joint
The movements at the cricothryoid joints are of two types-rotating and sliding. The most significant movements are rotational and occur about a lateral axis extending through the two joint. Either or both the cricoid and thyroid cartilages can rotate about this axis. One consequence of rotation is a change in the distance between the top of the anterior arch of the cricoid cartilage and the bottom of the laminae of the thyroid cartilage at the front. This is analogous to rotating the chin guard ( representing the laminae of the thyroid cartilage) and the visor (representing the laminae of the thyroid cartilage) on a motorcycle helmet. Secondary movements of the cricothyroid joints are of a sliding nature and can occur in those larynges that have oval-shaped cricoid facets. These movements are small and occur along the long axes of the cricoid facets.
Periodicity
The repetition of the g waveform is not perfectly periodic, but rather has very small variations in the periods of successive glottal cycles. Vocal fold vibration is therefore referred to as quasi-periodic. depends on the rate of vibration of the vocal folds, which can vary due to a number of factors like gender and age.
subglottal space
The subglottis or subglottic region is the lower portion of the larynx, extending from just beneath the vocal cords down to the top of the trachea. The structures in the subglottis are implicated in the regulation of the temperature of the breath. Narrowing of the subglottis is known as subglottic stenosis and may require a tracheotomy to correct
movement of cricoarytenoid joint
Two types of movements: rocking and sliding. Most significant: rocking. Rocking movements involve the arytenoid cartilages moving at right angles to the long axes of their articulating cricoid facets. This means that as the arytenoid cartilages rock on the cricoid cartilage their vocal processes move either upward and outward or downward and inward. Limited sliding movements can also occur along the cricoid facets. These movements involve small upward and inward or downward and outward adjustments of the arytenoid cartilages that follow the courses of the long axes of the cricoid facets.
State the average range of F0s that can be produced by a young adult.
Typically 3 octaves
Digastricus (extrinsic)
a double bellied muscle which draws the hyoid bone superiorly. Opens jaw Depresses mandible
Epiglottis
a flap of cartilage at the root of the tongue, which is depressed during swallowing to cover the opening of the windpipe.
laryngeal airway resistance
a measure of the opposition provided by the larynx to airflow through it. Such resistance is the property of the airway itself. Because the main constriction within the larynx is at the level of the vocal folds, this region of the larynx is the foremost contributor to laryngeal airway resistance. Ventricular folds are a secondary contributor. Resistance increases with increasing constriction and length of constriction. Airflow dependent
Cuneiform cartilages
a pair of club- or wedge-shaped elastic cartilages anterior to the corniculate cartilages that support the vocal folds and lateral aspects of the epiglottis
Corniculate cartilages
a pair of horn-like pieces of elastic cartilage located at the apex of each arytenoid cartilage
arch of cricoid cartilage
a semicircular structure, called the anterior arch, forms the front of the cricoid cartilage and is akin to a band on a finger ring.
vocal registers
a vocal register is a totally laryngeal event; it consists of a series or range of consecutive voice frequencies which can be produced with nearly identical phonatory quality; ... there will be little overlap in fundamental frequency and ... the operational definition of a register must depend on supporting perceptual, acoustic, physiologic and aerodynamic evidence
Suprahyoid (extrinsic)
above the hyoid bone
vocal fold stiffness
adjusted primarily in lengthening the vocal folds. This is accomplished primarily by contracting the cricothyroid muscles to increase their longitudinal tension. Similar to stretching of a guitar string. Can be changed by contracting muscles within the vocal folds themselves. Contraction of muscle fibers that lie within the lateral portions of the vocal folds (the thyromuscularis muscles) mainly stiffen those parts of the vocal folds and contractions of muscle fibers that lie within the medial portions of the vocal folds (thyrovocalis muscles) mainly affect those portions. The more forceful the contraction, the greater the stiffness.
transient sounds
airway protection Produced with HIGH Psg
glottal area function (closed phase)
approximately 13% of the cycle
glottal area function (closing phase)
approximately 37% of the cycle
glottal area function (opening phase)
approximately 50% of the vibratory cycle
deep lamina propria
body - many collagenous fibers. Bears analogy to cotton thread
whisper (laryngeal sound production)
can be accomplished with a long slit-like constriction, but is often accompanied by by other glottal configurations. Most frequent is the rearward facing Y configuration in which the membranous front parts of the vocal folds are firmly approximated, or not approximated at all and the cartilaginous rear parts of the vocal folds are relatively far apart. This is achieved by contracting the lateral cricoarytenoid muscles so that the vocal processes of the arytenoids cartilages toe inward, while leaving the arytenoid muscles less active or inactive. Quieter whispering will have low tracheal pressure, relatively high translaryngeal airflow, and low laryngeal airway resistance. Louder whispering will have a higher tracheal pressure and translaryngeal airflow, and around the same degree of airway resistance
upward movement of laryngeal housing
can be brought about by activation of one or a combination of muscles that includes the thyrohyoid, digastric (anterior and posterior bellies), stylohyoid, mylohyoid, geniohyoid, hyoglossus, and genioglossus muscles.
backward movement of laryngeal housing
can be brought through activation of one or a combination of muscles that includes the omohyoid (anterior and posterior bellies), digastric (posterior belly), and stylohyoid muscles.
Glottal Size and configuration
can change in length, diameter, area and shape Maximum glottal size can be achieved during a very deep inspiration following panting. Achieved mainly from contraction of the posterior cricoarytenoid muscles. Medium size - associated with resting tidal breathing Small - achieved by simultaneous contraction of the lateral cricoarytenoid muscles and the arytenoid muscles (transverse and oblique subdivisions) to form a narrow glottis along the length of the vocal folds or a small gap at the posterior part of the larynx if just the lateral cricoarytenoid muscles are activated.
downward movement of laryngeal housing
can result from activation of one or a combination of muscles that includes the sternothyroid, sternohyoid, and omohyoid (anterior and posterior bellies) muscles. Forward movements of the laryngeal housing can result from activation of one or a combination of muscles that include the sternothyroid, digastric (anterior belly), mylohyoid, geniohyoid, and genioglossus muscles
apex of arytenoid cartilage
capped with another small cone-shaped cartilage called the corniculate cartilage that is often fused to the arytenoid cartilage
cricotracheal ligament (extrinsic)
comprises the lowermost extrinsic connection to the larynx. This membrane extends around the bottom of the larynx between the first tracheal ring and the lower margin of the cricoid cartilage.
thyroepiglottic ligament (intrinsic)
connects epiglottis to the interior portion of the thyroid cartilage, near the thyroid notch functions as a fastener
glottal source spectrum
consists of (a) a series of of frequency components at consecutive integer multiples of the lowest frequency component (the fundamental fq/first harmonic) and (b) the relative amplitudes of the frequency components that decrease systematically as frequency increases
Cricothyroid (intrinsic)
consists of the pars recta and pars oblique
Squamous epithelium
cover - A thin stiff capsule of squamous epithelium that determines the outer shape of the vocal fold
superficial lamina propria
cover - a few elastic fibers; also called Reinke's space
Omohyoid (extrinsic)
depresses and retracts hyoid bone
simultaneous vocal attack
expiration and vocal fold adduction occur simultaneously -vocal folds reach the critical degree of adduction at the same time that the respiratory flow is adequate to support phonation -most efficient form of phonation
Vocal ligaments of the larynx (intrinsic)
extend between the angle of the thyroid cartilage and the vocal processes of the arytenoid cartilages and lie near the free margins of the vocal folds. These ligaments restrict the degree to which the thyroid and arytenoid cartilages can be separated from front to back
Lesser (minor) cornua
extend from the body of the structure and may be capped by tiny cone-shaped cartilages
anterior ceratocricoid ligament
extends backward into the front surface of the inferior cornu
Middle (medial) cricothyroid ligament (intrinsic)
extends between the top of the anterior arch of the cricoid cartilage and the bottom of the thyroid cartilage in the region of the angle of the thyroid cartilage. This ligament limits the degree to which the cricoid cartilage and thyroid cartilage can be separated vertically at the front
hyoepiglottic ligament (extrinsic)
extends between the upper back surface of the body of the hyoid bone and the lingual surface of the epiglottis. This ligament limits the degree to which these two structures can be separated from back to front
posterior ceratocricoid ligament
extends forward into the back surface of the cornu
anterior cricoarytenoid ligament
extends from the side of the cricoid cartilage to the front and side of the arytenoid cartilage. The ligament runs upward and backward and limits the degree to which the arytenoid cartilage can be moved backward
Posterior cricoarytenoid ligament
extends upward and toward the side from the back of the cricoid cartilage to the back of the arytenoid cartilage. This ligament limits the degree to which the arytenoid cartilage can be moved forward.
lateral ceratocricoid ligament
extends upward into the lower surface of the cornu.
Hyothyroid (thyrohyoid) membrane (extrinsic)
form a large interconnection between the hyoid bone and the upper margin of the thyroid cartilage of the larynx. This interconnection gives the appearance that the laryngeal housing proper is suspended from the hyoid bone. This hyothyroid membrane thickens toward the midline of the larynx at the front and is designated in that location as the middle hyothyroid ligament. The same membrane also thickens toward the back in the space between the greater cornua of the hyoid bone and the superior cornua of the thyroid cartilage. These thickenings are referred to as the later hyothyroid ligaments. Often embedded within each of these lateral ligaments is a small titiceal (grain of wheat) cartilage.
cricoid cartilage of larynx
forms the lower part of the laryngeal skeleton. It is a ring shaped structure located above the trachea. The cricoid cartilage has a thick plate at the back, the posterior quadrate lamina, which resembles a signet on a finger ring.
Bernoulli Effect
given a constant flow of air, at a point of constriction there will be an increase in pressure at the constriction, an increase in velocity of flow, and a decrease in air pressure perpendicular to the flow. As Vg increases, intraglottal P decreases. Result: reduced resistance to vocal fold elasticity
Describe the production of sustained turbulent sound at the level of the glottis: /h/
glottal fricative production can be achieved by positioning the vocal folds well inward to form a long slit-like constriction
inferior cornu of thyroid cartilage
have facets (areas where other structures join) on their lower inside surfaces that form joints with the cricoid cartilage. The inferior cornua straddle the cricoid cartilage like a pair of legs.
Cricothyroid joints
joints involved in lengthening and shortening the vocal folds to regulate F0
Vocal folds cartilaginous part (posterior) - (intrinsic)
lies between the vocal processes and most rearward point on medial surface of arytenoid cartilages; occupies 40% of length
Vocal fold membranous part (anterior) - (intrinsic)
lies between thyroid cartilage and tips of vocal processes of arytenoid cartilages; occupies 60% of the length
Greater (major) cornua
located toward the back of the structure and join with the superior cornua of the thyroid cartilage
fundamental frequency (F0)
manipulated primarily by the cricothyroid and thyroarytenoid muscles the lowest frequency of the glottal source spectrum, corresponding to the rate of vibration of the vocal cords. progressive reduction in relative amplitude with increasing frequency greatly limits the significance of very high frequency harmonics
adduction of vocal folds
movement of the vocal folds medially, toward the midline of the laryngeal airway.
modal register
normal voicing, vocal folds open for 40-50% of cycle
Mechanics of Vocal Fold Vibration
not caused by muscular contractions that pull them apart and force them back together again. Rather, movements of the vocal folds are passive and akin to the movements of the lips when air is blown between them. Muscular forces are important, but only in the sense that they set the vocal folds (or lips) in position to be moved passively to and fro by aeromechanical forces.
Pars recta (intrinsic) Origin, insertion, fiber course, innervation, action
origin: lower anterior border of the cricoid arch, insertion: thyroid lamina, fiber course: vertically, innervation: superior laryngeal nerve, action: brings the cricoid and thyroid closer together through a rocking movement
pars oblique (intrinsic) Origin, insertion, fiber course, innervation, action
origin: on the lower anterior border of the cricoid, insertion: inferior cornu of the thyroid, fiber course: upwards and backwards, innervation: superior laryngeal nerve, action: brings the thyroid and cricoid closer together, primarily through a rocking movement, but sometimes a forward sliding movement
Lateral cricoarytenoid (LCA) - intrinsic Origin, insertion, fiber course, innervation, action
origin: the arch of the cricoid, insertion: the muscular processes of the arytenoid and the front surface of the arytenoids, innervation: inferior laryngeal nerve, fiber course: backwards and upwards, action: medial compression- brings the arytenoids towards the midline by drawing the muscular process forward and drawing the vocal processes medially.
Posterior cricoarytenoid (PCA) - intrinsic Origin, insertion, fiber course, innervation, action
origin: the back surface of the cricoid lamina, insertion: muscular processes of the arytenoids, innervation: recurrent laryngeal nerve, fiber course: upward and to the sides, action: rocks the arytenoids away from the midline, which opens the glottis
Thyromuscularis - intrinsic Origin, insertion, fiber course, innervation, action
origin: the bottom of the thyroid angle on the back, insertion: front sides of arytenoids, fiber course: parallel to the vocal ligament, innervation: inferior laryngeal nerve, action: brings the thyroid and arytenoid closer together by rocking the arytenoids towards the midline, which in turn relaxes the vocal ligament
Vocalis (thyrovocalis) - (intrinsic) Origin, insertion, fiber course, innervation, action
origin: vocal processes of the arytenoids, insertion: the vocal ligament, fiber course: parallel to vocal ligament, innervation: inferior laryngeal nerve, action: tenses the anterior vocal ligament and relaxes the posterior vocal ligament
Oblique arytenoid (paired) - (intrinsic) Origin, insertion, fiber course, innervation, action
originates from the back and side surface and the muscular process of the arytenoid and inserts in the apex of the opposite arytenoid, fiber course: most run diagonally and some fibers extend upward to become aryepiglottic muscles, innervation: recurrent laryngeal nerve Contraction of the oblique arytenoid pulls arytenoid cartilages toward each other in a tipping action, which adducts the vocal folds. Also acts as a sphincter for the superior opening of the larynx
Anterior (upper) belly - omohyoid (extrinsic)
originates from the same tendon near the sternum and inserts in the lower edge of he greater cornu of the hyoid bone Contraction pulls downward and backward on hyoid bone
Posterior (lower) belly - omohyoid (extrinsic)
originates from the upper edge of the scapula and courses horizontally and inward to insert on a tendon near the sternum
Transverse arytenoid (unpaired) - intrinsic Origin, insertion, fiber course, innervation, action
originates on the back surface of one arytenoid and inserts at the same location on the other arytenoid, fiber course: horizontally/medialy, innervation: recurrent laryngeal nerve Contraction of the transverse arytenoid pulls arytenoid cartilages toward each other, which adducts the vocal folds
Ventricular ligaments (intrinsic)
place limits on the degree to which the thyroid and arytenoid cartilages can be separated from front to back
Cricoarytenoid joints
positioned near the top of the larynx and involve articulations between the facets on the undersurfaces of the arytenoid cartilages and sloping rims of the cricoid cartilage. Synovial membranes encapsulate these joints and lubricate them
vocal process of arytenoid cartilage
projects toward the thyroid notch; where the vocal folds attach in the anterior
Harmonics
relative amplitude decreases 6-12 dB for each octave increase in frequency F(0)= the first harmonic, the other frequencies of the glottal source spectrum are whole number multiples of F(0). H2=F(0)*2, H3= F(0)* 3, H4=F(0)*4
extrinsic laryngeal muscles
responsible for elevating and lowering the larynx in the neck during respiration, phonation, and swallowing muscles with one attachment in the larynx and one outside
Lateral hyothyroid ligaments (extrinsic)
round elastic cord, which forms the posterior border of the hyothyroid membrane and passes between the tip of the superior cornu of the thyroid cartilage and the extremity of the greater cornu of the hyoid bone.
aryepiglottic folds (intrinsic)
run between the aryepiglottic cartilages and the epiglottis and envelop the aryepiglottic muscles and a pair of small cuneiform (wedge-shaped) cartilages
ventricular folds (false vocal cords) (intrinsic)
superior pair, function in holding breath against pressure in thoracic cavity
hyoid bone
technically the hyoid bone is not a part of the larynx. Nevertheless it is an integral component in many laryngeal functions. The hyoid bone is described as a free floating in the sense that it is not attached to any other bone. It is a U-shaped structure that is positioned horizontally within the neck, its open end facing toward the back. The hyoid bone consists of a body and two pairs of greater and lesser horns (cornua) that project upward
Superior cornu (thyroid cartilage)
the back edges of the thyroid laminae extend upwards into two long horns, called the superior cornua, and downward into two short horns call the inferior cornua. The superior cornua are coupled to the hyoid bone
Glottis (membranous portion)
the back part of the glottis; occupies about 40% of length of the vocal folds and lies between the tips of the vocal processes of the arytenoid cartilages and the most rearward points on their medial surfaces
muscular process of arytenoid cartilage
the base also includes a rounded stubby projection that extends toward the back and side. The undersurface of each muscular process has a facet that articulates with one of the upper facets of the cricoid cartilage (insertion of lateral cricoarytenoid muscle)
Glottis (membranous portion)
the front part of the glottis; occupies 60% of the length of the vocal folds. It lies between the thyroid cartilage and the tips of the vocal processes of the arytenoid cartilages and courses along the vocal ligaments.
Significance of the g waveform
the g waveform is periodic, meaning that it's characteristic shape repeats over time. The rate at which it repeats over time is the fundamental frequency (F0) of vocal fold vibration, or how many times per second the vocal folds go through complete cycles of vibration. the slope of the opening phase is shallower than the slope of the closing phase, making each cycle appear as if it is "leaning to the right." The steepness of the closing phase reflects how rapidly the vocal folds come together at the end of each cycle. The more rapidly the vocal folds come together, the steeper the closing part of the g wave. The g waveform shows some portions where the vocal folds are apart (where airflow is coming through the glottis) and some portions where the vocal folds are approximated. The ratio of open to closed time for each cycle is around 60% open. This may be important in determining how much the source signal is periodic and aperiodic. This is also important in considering the physiological and acoustical basis of pathological voice quality.
Laryngeal Housing
the housing of the larynx can move within the neck. Although it can move in all directions the most important movement is vertical. The laryngeal housing can also be shifted forward or backward within the neck, having a potential for greater forward than backward movement from its resting position. Extrinsic and supplementary laryngeal muscles are responsible for moving and stabilizing the laryngeal housing.
intrinsic ligaments and membranes (larynx)
the intrinsic ligaments and membranes of the larynx are those that connect laryngeal cartilages to one another These ligaments and membranes are important in regulating the extent and direction of movement of the laryngeal cartilages in relation to one another
thyroid cartilage of larynx
the largest of the laryngeal cartilages and forms most of the front and sides of the laryngeal skeleton. This cartilage provides a shield-like housing for the larynx and offers protection for many of its structures
angle of thyroid cartilage
the line of fusion between the two plates (laminae) is called the angle of the thyroid.
Cricothyroid articulator facets (lower 2)
the lower two facets, one on each side at the same level, are positioned near the junction of the posterior quadrate lamina and anterior arch. Each of these facets articulates with a facet on one of the inferior cornua of the thyroid cartilage.
vocalis muscle (intrinsic)
the main body of the vocal fold which may be likened to a bundle of stiff rubber bands
Laryngeal opposing pressure (medial compression) - 3 parts
the measure of the opposition provided by the larynx to translaryngeal air pressure (the air pressure difference between the trachea and the pharynx), when the larynx is closed airtight. Three components: a. Compressive muscular pressure that squeezes the closed larynx and holds the vocal folds together. B. surface tension between the apposed surfaces of the moist vocal folds that holds them together and c. gravity that weighs down the vocal folds and influences them differently in different body positions (or different gravity fields) Of these three, compressive muscular pressure is the greatest contributor to laryngeal opposing pressure.
laryngeal prominence
the notch is located just above the most forward projection of the cartilage, an outward jutting called the thyroid prominence or Adam's apple
Vocal fold effective mass
the overall mass of the vocal folds does not change, the effective mass may change in the sense that only part of the vocal fold mass may participate in a given activity. Full mass and effective mass are the same when the vocal folds are fully abducted and maximally elongated. Example: forceful medial compression by contraction of the lateral cricoarytenoid muscles can reduce the effective mass of the membranous portions of the vocal folds in vocal fold vibration.
Quadrangular membrane (intrinsic)
the part of the elastic membrane that lines the region from the ventricular folds to the laryngeal aditus connects the epiglottis, thyroid cartilage, arytenoid cartilages, and corniculate cartilages to one another. This membrane is paired left and right and thickens significantly toward the bottoms of the pair to form the ventricular (false vocal fold) ligaments.
Phonation
the production of sound by structures in the upper respiratory tract
Middle hyothyroid ligament (extrinsic)
the thickest part of the hyothyroid ligament
notch of thyroid cartilage
the upper part of the structure contains a prominent V-shaped depression termed the thyroid notch that can be palpated at the front of the neck. This notch is located just above the most forward projection of the cartilage, an outward jutting called the thyroid prominence or Adam's apple.
vestibule of laryngeal cavity
the upper region of the laryngeal cavity is bounded below by the ventricular folds and above by the laryngeal aditus. This region is called the laryngeal vestibule (cavity approaching a cavity). The configuration of this vestibule is roughly that of a funnel, the lumen of which increases in size toward the upper end.
Cricoarytenoid articulator facets (upper 2)
the upper two facets of the cricoid cartilage, one on each side at the same level, are located on the sloping rim of the posterior quadrate lamina. Each of these facets articulates with a facet on the undersurface of one of the arytenoid cartilages.
Ventricle of laryngeal cavity
the vocal folds and ventricular folds have a sinus (depression) between them. This sinus is called the laryngeal ventricle and constitutes a horizontal ouch in each sidewall of the laryngeal tube. Extends most of the length of the vocal folds. Toward the front of the larynx they course upward into saccules that are richly endowed with mucous glands. These glands contain mucus that lubricates the vocal folds.
glottal airflow
the volume of air flowing through the glottis per unit of time symbolized as Vg. Vg reflects movement of air molecules, which results in sound pressure waves
Lamina of cricoid cartilage
thick plate at the back of the cricoid cartilage , which resembles a signet on a finger ring.
aryepiglottic (intrinsic) Origin, insertion, fiber course, innervation, action
this muscle is a continuation of the oblique muscle Origin: on the arytenoid apexes, insertion: sides of the epiglottis, fiber course: vertically, innervation: recurrent laryngeal nerve Contraction of the aryepiglottic muscle pulls the epiglottis backward and downward to cover the larynx
vertical phase difference
timing difference between the inferior and superior borders of the vocal folds as they open and close during vibration Conceptualized as two primary movements: one translational and one rotational. The translational mode is the lateral movement of the vocal folds away from the midline and back again. The rotational mode is the rotation of the vocal fold cover around a pivot point located somewhere between the bottom and top of the medial surface
intermediate lamina propria
transition (body/cover) - many elastic fibers. Likened to a bundle of soft rubber bands
laryngeal joints
two pairs of joints: cricothyroid joint and cricoarytenoid joint
Vocal folds (intrinsic)
two prominent shelf-like structures that extend from the sidewalls of the laryngeal cavity into the laryngeal airwary. Each vocal fold has a front attachment near the midline of the thyroid cartilage and a rear attachment to the vocal process of the arytenoid cartilage on the same side. Greater tension in the vocal folds creates more rapid vibrations and higher pitched sounds. Lower tension causes slower vibration and a lower pitch.
Thyroid Lamina
two quadrilateral plates, are fused together at the front of the thyroid cartilage and diverge widely (more so in women than in men) toward the back. The configuration of the two thyroid lamina resembles the bow of a ship.
lengthening vocal folds
vocal fold length changes mediated through the cricothyroid joints. Active vocal fold lengthening is accomplished primarily by forward directed forces through contraction of the cricothyroid muscles (with possibly backward-directed forces exerted by the posterior cricoarytenoid muscles).
quasiperiodic
vocal production relies on quasi-periodic vocal fold vibration governed by nonlinear interaction between an energy source (the breather apparatus) and the structures being vibrated (the vocal folds)
digastricus posterior (extrinsic)
• Origin: mastoid process of the temporal bone (behind ear) • Insertion: hyoid bone • Action: draws hyoid up and back
