Transcript Phonation

Phonation
•
ANATOMY
1. LARYNX
•
Description:
–
•
is musculocartilaginous structure
Location:
–
–
–
–
lies on top or/superior to trachea
located midline on anterior neck
Palpate thyroid notch which is anterior
attachment of the vocal folds.
Thus larynx located between the hyoid
bone (superiorly) and trachea (inferiorly)
•
–
located at about the level of the 3rd, 4th,
5th, & 6th cervical vertebrae
This position may vary according to:
sex, age, head position, laryngeal activity
Supraglottal
Air from lungs is
perturbed by the
opening and closing
of the approximated
vocal folds.
Laryngeal
MEP
Respiratory
Ps
From
www.gbmc.org/voice/larynx/anatomyphysiologyofthelarynx.cfm
• Function:
– Biological
• It is a component of respiratory system,
thus functions as protective device for
lower airway.
• Acts to
– (1) prevent foreign objects from
entering lungs,
– (2) prevents air from escaping the
lungs,
– (3) forcefully expels foreign
substances which threaten to enter
larynx or trachea.
– Nonbiologic
• sound production
– only functions as sound generator
when it is not fulfilling biological
functions. It represents variable
resistance to the flow of air.
– What do I mean by variable
resistance? Vocal fold adduct to
provide varying/changing amounts of
resistance to outward flowing air.
• Sound Generation: A brief description
• Vocal folds
– Description: long bands of muscle tissue
– May be lengthened, shortened, tensed,
relaxed, abducted, or adducted
– During quiet breathing, VFs are:
– A quick, deep inhalation for speech occurs.
Then exhalation (for speech) starts.
• Generation of air pulses
• Folds are either completely adducted (yet loosely) or
slightly less than completely adducted.
• Air flows out of lungs producing increasing pressure
beneath folds.
• When subglottic pressure is sufficient, folds are
blown apart
• A puff of air is released.
• Release of air results in sudden drop in pressure
beneath folds.
• Elasticity of tissue, plus reduction of air press.,
causes folds to come together again.
• This is one cycle of vocal fold vibration.
• These air pulses excite the supralaryngeal air column
so as to produce a complex tone.
• Usual rate in males = 125 cps, females = 210 cps,
higher in children.
• cps =
–
http://stanfordhospital.org/clinicsme
dServices/clinics/otolaryngology/lar
yngology/clinicalPicturesMovies.ht
ml
•
Supportive Framework for Larynx
1. Hyoid bone:
•
•
•
U-shaped
Unique in that not attached directly to
any other bone in skeleton, rather bound
in place by network of muscles and
ligaments
Muscles which attach to hyoid bone and
suspend it comprise the hyoid sling
muscles
•
•
•
•
Muscle from tongue* and mandible above,
muscles & ligaments from temporal bone
approach from behind and superiorly; while
extrinsic laryngeal muscles from below
attach to hyoid, as do muscles from
sternum and clavicle.
Hyoid is a highly mobile structure
Larynx is somewhat suspended from it
Serves as superior attachment for some
extrinsic laryngeal muscles (originating
outside of part)
• Anatomy: located in neck horizontally, at level
of C3. Composed of:
– Corpus: body, roughly quadrilateral in
shape--convex anterior surface and concave
posterior surface
• Why does it have this form or
structure?
– Greater horns (cornua)--posteriorly
(dorsally) directed limbs
– diminish in size as go posteriorly
– terminate as tubercles (sm. rounded
projection), which articulate indirectly with
superior horns of thyroid cartilage.
– Lesser horns--at junction of corpus and
greater horns
• www.getbodysmart.com Select skeletal
system; skull bones
1B. The picture is a superior view of
the hyoid bone.
Label 1, 2, and 3.
State the plane.
•
•
CARTILAGENOUS FRAMEWORK of
LARYNX
Comprised of 9 cartilages
–
3 are unpaired, rather lg.,
–
3 are paired, and smaller (3 X 2 = 6 + 3 = 9)
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Cartilages of made up of either:
•
(a) hyaline cartilage (ossifies as we turn
older--means larynx rather soft, pliable,
flexible, capable of growth during
childhood/adolescence, later becomes
bonelike and quite brittle) or
•
(b) elastic cartilage
1.
Thyroid cartilage:
•
Largest of laryngeal cartilages--name
means shieldlike
A. Thyroid laminae--two quadrilateral
plates--fused at midline--form
anterior and lateral walls of larynx
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LANDMARKS
Angle of thyroid--pt. of juncture
between 2 laminae--@ 80 degrees in
males, 90 degrees in females
Thyroid notch= V-shaped
Thyroid prominence (Adam's apple)-anterior projection
Pic from anatomy.med.umich.edu/home.html
B. Superior cornu--superior horns
directed upward, backward, and
medially--attached thru ligament to
hyoid bone--Are extremely variable in
size from pt. to pt., may even be
missing
C. Inferior cornu--shorter and thicker
than superior--directed downward and
medially--articulate with cricoid
cartilage by articular facets located on
medial surface. 90% of people have
oblique tendon that bridges the
superior and inferior tubercles (It is
place of origin for extrinsic m.=
thyrohyoid & sternothyroid)
D. Foramen--found in 1/3 pop.--allows
blood vessel access to interior of
larynx
2B. Name parts of the
thyroid cartilage, numbers
1-5
2. Cricoid cartilage: (Gr. krikos = ring)-hyaline cartilage--located immediately
above the uppermost tracheal ring.
Smaller but stouter than thyroid
A. cricoid lamina--likened to signet ring-occupies space between posterior
margins of thyroid; has articulatory
facets for arytenoid cartilages.
B. anterior arch--has articular facets
for articulating with inferior horns of
thyroid. Joint formed by this
articulation permits thyroid or cricoid
to rotate about an axis. This
movement is very important for pitch
changing.
2A
LABEL 1, 2A, 2B, 3
2B
• 3.
Arytenoid cartilages: located on cricoid
cartilage--hyaline cartilage--resemble 3sided pyramid
A. muscular process--on posterolateral
surface--is rounded facet that
articulates with cricoid--pt. of
attachment for some imp. laryngeal
muscles.
b. vocal process--anterior angle, pointed
projection--the vocal ligament, an
important part of vocal fold, inserts on
the vocal process. (see previous slide)
Muscular
process
Locate muscular process on
this slide.
•
Corniculate cartilages: apexes of
arytenoid cartilages are capped by this pair-name describes hornlike shape--quite large in
animals; in humans are probably vestigial, once
serving a protective function--sometimes are
absent
4.
• 5.
Epiglottis: flexible, leaf-like structure
made up of elastic cartilage.
• Location:
–
Just behind hyoid bone and root of tongue.
Attaches to thryoid cartilage at angle, just
beneath thyroid notch by means of a ligament.
Broadest portion connects to hyoid bone
(hyoepiglottic ligament). Anterior surface is
curved forward. Connects to tongue by median
and lateral glossoepiglottic ligaments
– Function: prevent food from entering the
larynx during deglutition
• Contributes very little to speech*
Name the view/plane
– Valleculae (L. = sm. valleys)--pits formed
between epiglottis and root of tongue, one
on either side of median glossoepiglottic
ligament. Food may fall into valleculae and
remain before or after a swallow. See next
slide
• Cuneiform cartilages: (Cunie = wedge
shaped) Are imbedded in aryepiglottic folds
(fold of membrane which extends from
sides of epiglottis to apexes of arytenoid
cartilages= entrance to larynx)--anterior
and lateral to corniculate cartilages--may
be absent.
– Function: lend support to aryepiglottic
folds and stiffen them to help maintain
the opening to the larynx
Cuneiform
Corniculate
Posterior Cricoarytenoid
• Review:
• www.ncvs.org/index.html
– Tutorials, Young Explorers
– http://www.ncvs.org/ncvs/tutorials/younge
xp/fantasticvoyage.html
• mywebpages.comcast.net/wnor/lesson
11.htm
• http://stanfordhospital.org/clinicsmed
Services/clinics/otolaryngology/laryng
ology/clinicalPicturesMovies.html
• www.getbodysmart.com
– Select Respiratory System
– Larynx
• Take special notice of animations of intrinsic
laryngeal muscles
• LARYNGEAL JOINTS
• A. cricoarytenoid joint: permits rocking
motion and some gliding action
– rocking motion causes an upward and outward
motion of the vocal process during abduction and
an inward and downward swing during adduction.
– Medial and lateral sliding of the arytenoid
cartilage toward or away from midline,
which brings the arytenoids toward or away
from each others.
– http://www.slpanimation.com/3dvoice/
• B. cricothryoid joint: pivot joint-primary action is rotational.
– In neutral position, ligaments surrounding
joint are somewhat slack, so limited gliding
action can take place.
– Rotational and gliding action place v. folds
under increased tension, increasing pitch.
– Action decreases distance between thyroid
and cricoid, and increases distance between
vocal processes of arytenoids and angle of
thyroid
• MEMBRANES AND LIGAMENTS
• A. Extrinsic: connect laryngeal cartilages
with other adjacent structures
– 1. hyothyroid membrane and ligaments-larynx seems to be suspended from
hyothyroid--located between hyoid and
superior border of thyroid--portions are
thickened and called ligaments.
Hyothyroid
ligament
•
– 2. hyoepiglottic ligament--unpaired,
midline--extends from anterior surface of
epiglottis to upper border of body of hyoid
A
•
B
– 3. cricotracheal membrane--connects
lower border of cricoid with 1st tracheal
ring
• B. Intrinsic: interconnect various laryngeal
cartilages, help to regulate extent and
direction of movements--almost all originate
from broad sheet of connective tissue called
elastic membrane (lines almost entire larynx)
•
1. conus elasticus--lower portion of
elastic membrane--cavity below vocal
folds is cone-shaped (thus name)
• continuous sheet of membrane connects
thyroid, cricoid, and arytenoid cartilages
with one another. Extends from
superior border of arch and lamina of
cricoid to true vocal folds.
Cuneiform
Corniculate
2. quadrangular membrane (shape)--arise
from lateral margins of epiglottis (i.e.,
superior margins of QM also called
aryepiglottic folds) and thyroid cart. near
angle--fibers course posteriorly downward,
and attach to corniculate cartilages and
arytenoids. Inferiorly, terminate as free,
thickened borders called ventricular (or
vestibular) ligaments.
Cuneiform
Corniculate
Ventricular
Note the Aryepiglottic folds
• C. Membrane: larynx lined with mucous
membrane that is continuous with lining of oral
cavity and trachea. It is rich in mucous glands
in area between vocal and ventricular ligaments
• INTERIOR OF LARYNX
• A. Laryngeal cavity: goes from aditus
laryngis (aditus = entrance) to inferior border
of cricoid cartilage. Aditus = triangular in
shape, bounded by epiglottis in front,
aryepiglottic folds, and apexes of arytenoids
posteriorly.
Posterior Cricoarytenoid
• 1. pyriform sinus: bounded laterally by
thyroid cartilages and membrane, medially by
aryepiglottic folds (www.radiologyassistant.nl)
• 2. rima glottidis or glottis: space between
vocal folds. Some include the vocal folds and
the space as the glottis.
• Name the plane shown below.
vallecula
Pyriform
sinus
mywebpages.comcast.net/wno
r/lesson11.htm
• INTERIOR OF LARYNX CONT.
– 1. ventricular folds: are soft and flaccid,
incapable of becoming tense.
• Attach to angle of thyroid, just beneath
attachment to epiglottis. Posteriorly attach
to arytenoids. Move with arytenoids, but are
further apart than vocal folds during
phonation. They do not vibrate under normal
conditions. Space between ventricular folds
called ____________
• Clinical note:
• B. Supraglottic region: between
ventricular folds & aditus is called
vestibule. Sm. region between
ventricular folds and vocal folds called
ventricle.
• C. Subglottal region: bounded above by v.
folds and below by inferior margin of cricoid
cartilage--lined with ciliated tissue, extending
into trachea and bronchi. Cilia beat toward
pharynx in L., helping to remove accumulations
of mucus and foreign matter.
– 1. vocal folds: true lie parallel to and just
beneath ventricular folds, separated by
laryngeal ventricle.
– Origin = thyroid cartilage, near angle, below
notch--anterior commissure (anterior
attachment) of folds is common, diverge as
course posteriorly toward posterior
commissure; Insert on arytenoid cartilages.
Borders are free.
– Membranous portion of vocal folds appear
to be most active in vibration, altho
cartilagenous portion also vibrates.
– Appearance:
– 2. glottis: variable opening between folds.
Anterior portion bounded by vocal ligament
called membranous glottis, posterior 2/5 is
bounded by vocal process and medial
arytenoid cartilage = cartilaginous glottis.
At rest glottis is @ 8mm in males, during
forced inhalation this value may double.
Muscles of Larynx
Muscles are either intrinsic or extrinsic.
We will only discuss intrinsic.
• 1. Thyroarytenoid (adductor, tensor,
or relaxer):
• Some texts list two separate muscles:
Thyromuscularis and Vocalis.
• Origin = inner surface of angle of
thyroid.
•
– * Superior fibers (vocalis) flank vocal
ligament, course backward and insert into
vocal process of arytenoids (lateral and
inferior aspect).
– *Inferior fibers (thyromuscularis) are
twisted, course in lateroposterosuperior
direction, insert along base of arytenoid
cart.
Func = act as regulator of longitudinal tension.
– Contracting alone = relax v. folds, and assist
in closing glottis (by pulling forward on
muscular process).
– When contraction opposed by other
intrinsic m., then =
– www.getbodysmart.com
• Respiratory system
• Larynx
• Production of voiced sds
Label 1-6
• Check movement on www.getbodysmart.com
• For dissection pictures go to:
zemlin.shs.uiuc.edu/
• Select larynx 1 or larynx 2
3B. Label 1-2, 4-9
•
•
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•
2. Posterior Cricoarytenoid M. (abductor)
Just one abductor m.
Origin = posterior surface of cricoid
Insertion = muscular process of arytenoids.
Function:
Two m. act as antagonists to PCA: lateral
cricoarytenoid, and arytenoid muscles.
• Check movement on www.getbodysmart.com
• 3. Lateral Cricoarytenoid M. (adductor,
increases medial compression)--slightly fanshaped, located deep to thyroid cartilage.
• Origin = upper border of anterolateral arch of
cricoid, Course = upward, backward
• Insertion = muscular process of arytenoid.
• Func = rotates arytenoids to bring vocal
processes toward midline. Also instrumental in
regulating medial compression of v. folds.
Acting unopposed, will shape glottis for
whisper.
• Check movement with www.getbodysmart.com
• 4. Arytenoid M. (adductors)--located on
posterior surface of arytenoids. Usually
described as having 2 parts:
•
A. Oblique arytenoid = more superficial
than other part.
• Origin = m. process -- two m. cross ea. other
like letter X, Insert = near apex of opposite
arytenoid.
– Func : approximate arytenoids and regulate
medial compression.
•
B. Transverse arytenoid = stout m.
• Origin = lateral margin and posterior surface
of one arytenoid, course horizontally, Insert =
lateral margin and post. surface of other
arytenoid.
– Func = approx. arytenoids by causing them to
slide along axis toward midline.
• 5. Cricothryoid (tensor)--only one other m.
which tenses or elongates v. folds
(thyroarytenoid)--Fan-shaped--Origin =
anterolateral arch of cricoid--fibers diverge
into two distinct parts.
•
A. Pars oblique--courses upward and
back, Insertion = inferior horn of thyroid
•
B. Pars recta--fibers located anterior to
pars oblique--courses nearly vertically,
Insertion = inner aspect of lower margin of
thyroid lamina
• Func: contraction of anterior fibers =
decrease distance between cricoid arch and
thyroid cart.; If thyroid fixed, raises cricoid;
If cricoid fixed, thyroid tilts downward. All
result in increasing distance between thryoid
and v. processes of arytenoids resulting in
elongation of v. folds, placing them under
increased tension, an action necessary for
pitch changes.
• Label 1-7
7
• http://www.ncvs.org/ncvs/tutorials/voiceprod/
tutorial/model.html
– Models of vocal fold oscillation
• http://www.medicine.uiowa.edu/otolaryngology/
cases/index1.htm
– Videos of normal larynx and presents cases and
videos of those with vocal pathologies
• http://www.voicedoctor.net/media/video/i
ndex.html
– Videos of vocal pathologies
•
Structure of the Vocal Folds
3 layers
1.
Cover: epithelium and superficial layers of the
lamina propria
– Epithelium is 8 layers thick to protect
delicate underlying tissues from abrasion
caused during phonation and flow of air into
and out of lungs.
– Superficial layer of lamina propria called ?
» this layer vibrates the most during
phonation
» If it becomes stiffened due to
pathologies, the result is dysphonia*
2. Transition: Intermediate (elastic
fibers) and deep layers (likened to
cotton fibers) of lamina propria; also
called ?
• Composed of elastic and
collagenous fibers
• Provides for resiliency and
extensibility
• Conclusion: Vocal ligament provides
longitudinal stability to VFs and
enables them to be responsive to
the intrinsic laryngeal muscles,
especially the TA
3. Body: vocalis portion of TA muscle
(like bundle of stiff rubber bands)
Cover
Epithelium
Superficial
Superficia
l Intermediate
Deep
Deep
Body
TRANSITION
Transition
Epithelium
Deep .
Vocalis
(Thyroarytenoid)
Vocalis
Lamina Propria= superficial,
intermediate, and deep
layers
• Reinke’s edema
FYI
Reinke’s edema results from smoking—it
is simply not found in persons who have
never smoked. It may represent a
specialized tissue reaction to thermal
insult.
It involves the entire length of one or
both vfs.
• Innervation of the laryngeal muscles
• Vagus nerve: Vagus originates from nucleus
ambiguous of medulla; exits cranium thru
jugular foramina; divides into 3 branches:
• 1. Pharyngeal nerve: supplies all muscles
of the soft palate, except the tensor
veli palatini (CV innervation for tensor)
• 2. Superior laryngeal nerve. Divides
into internal and external branches.
– a. Internal laryngeal nerve.
» Enters thru hyothryoid
membrane.
» Sensory function = Sensory
fibers to mucous membrane
lining larynx above v. folds,
epiglottis, vallecula, and
vestibule of larynx, aryepiglottic
folds.
– b. External laryngeal nerve
» Motor function =
• 3. Recurrent laryngeal nerve.
– Motor function = it innervates all
intrinsic m. of larynx except
cricothyroid
– Sensory = Innervates sensory receptors
in mucous membrane below v. folds
•
Pharyngeal branch not shown in figure.
Internal
superior
laryngeal
branch
External superior
laryngeal branch
• Be able to name the nerves/muscle/membrane
shown below.
a
b
e
d
c
– Lesions to Vagus nerve and its branches:
1. Lesions above pharyngeal branch:
Adductor paralysis with
palatopharyngeal paralysis.
Unilateral: breathiness or whispered voice quality, hoarseness (due to asynchronous
vibration), reduced loudness (inefficient glottal closure) and low pitch with possible pitch
breaks, occassionally diplophonia; mild-to-moderate hypernasality and nasal emission
(due to impaired VP function).
Bilateral = severe breathiness or aphonia (if bilateral paralysis is total); weak cough or
glottal attack; hypernasality/nasal emission more severe; both folds fixed in abductor
position; PROTECTION of airway is of primary concern. ASSOCIATED SYMPTOMS:
Depend on extent of weakness and whether involvement is unilateral or bilateral
•Difficulty swallowing—due to palatal and pharyngeal muscle involvement
•Nasal regurgitation—VP incompetence
•Aspiration of secretions—due to palatopharyngeal and laryngeal involvement.
Tracheostomy may be necessary if aspiration becomes a problem.
2.
Lesions below pharyngeal branch
involving SLN and RLN: Adductor
paralysis.
–
Symptoms: Same voice symptoms
as described above, but without
________. Fold usually in
intermediate position. No VP
incompetence.
– 3. Lesion affecting SLN only
• Unilateral lesion:
• Voice =
• Associated symptoms
• Bilateral lesion:
• Voice =
• Associated symptoms—same as
above
SLN LESIONS
ETIOLOGY: Surgical trauma, accidental trauma, benign
thyroid disease.
UNILATERAL: Both folds adduct on phonation, but fold on
affected side will appear shorter, and an asymmetric lateral
shift of epiglottis and anterior larynx toward unaffected side
is seen.
VOICE: mild breathiness and hoarseness, normal or mildly
reduced loudness, and mild inability to alter pitch often only
noticeable when pt attempts to sing. Pt may complain of
vocal fatigue.
ASSOCIATED SYMPTOMS: laryngeal anesthesia can
result in mild postdeglutition cough, choking, or aspiration,
or a mild cough after swallowing; often symptoms aren’t
constant or obvious thus may not be reported by pt.
NO surgical intervention
NO voice tx
Bilateral lesion = absence of tilt of thyroid cartilage on
cricoid cart. during phonation, folds appear shorter than
normal, epiglottis will overhang and obscure anterior
portion of folds, will be bowing of folds. Voice =
breathiness, hoarseness (mild to moderate), loudness will
be reduced, ability to alter pitch will be moderately to
severely impaired (serious prob. with singing). Pt may
complain of vocal fatigue.
NO MEDICOSURGICAL MANAGEMENT; NO VOICE TX
4. Lesion affecting RLN only
• A. Unilateral RLN lesion
• Voice
• Associated Symptoms
Unilateral Abductor paralysis—affected VF in
paramedian position due to action of CT. CT exerts
stretch on folds anteroposteriorly, acts as adductor,
thus pulling v. folds closer to midline; abductor muscle
nonfunctioning, so cannot pull VFs and widen glottis.
May have weak cough or glottal attack.
ETIOLOGY: Intrathoracic malignant tumor,
aneurysms, mital stenosis which causes left auricle to
enlarge and impinge on Vagus, trauma to neck,
idiopathic (80% resolve within 6 months to 1 year).
VOICE: voice usually not affected because both VFs
can approximate at midline. If voice affected, will
have mild breathy and mild hoarse quality, with
slightly reduced loudness and occasional diplophonia.
ASSOCIATED SIGNS: May experience shortness of
breath during physical activities due to narrowed
airway (during periods of deep respiration).
MEDICOSURGICAL—delay for 6-12 months. Rarely
is surgery indicated in unilateral abductor paralysis.
Voice TX: generally doesn’t require tx. Pts who use
voice professionally may require instructions on
increased breath control, how to increase intensity,
and how to maintain a relaxed vocal tract.
Unilateral VF paralysis
video:
http://www.youtube.com/watch?v=dEl3rNdMWkY
Muscles and actions
• Adduction (2 major muscles):
– A.
– B.
• Abduction
• Raising fundamental frequency
(pitch)
• Lowers fundamental frequency
(pitch)
a
b
d
c
e
a
b
d
e
c
f
• Do not use “vocal fold” as an
answer below.
1
6
2
7
3
4
8
5
9
10. Name the plane shown.