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172 O. Ekberg
https://t.me/med1917
is a complex interaction of excitatory and inhibitory
stimuli. It should be remembered that denervation of
smooth musculature leadstocontraction. It maywellbe
that these patients have lost contact between the dorsal
motor nucleus of the vagus nerve and the smooth
muscle of the esophagus and that we are observing the
activity of the enteric nervous system. Such corkscrew
esophagus is notthe same asnutcracker esophagus seen
in young patients. Nutcracker esophagus has normal
transportation but an increased contraction pressure.
Diffuse esophageal spasm (DES) and corkscrew contractions differ in such a way thatit isconsidered thatin
the DES the peristaltic contraction obliterates the
lumen, whereas in the corkscrew esophagus contraction does not obliterate the lumen. However, DES and
curling or corkscrew dysfunction may be closely related. They both fall into the category of spastic esophageal dysfunction.
8 Gastroesophageal Reflux
It is important to realize that gastroesophageal reflux
Fig. 4 Esophageal dysmotility is common in the elderly. This
patient shows multiple nonpropulsive contractions of the distal
esophagus. This may, as in this patient, be very symptomatic.
This 81-year-old woman vomited halfway through every meal.
The barium study shows retention due to the motor dysmotility.
Other patients might show similar esophageal dysfunction but
do not vomit and are not otherwise symptomatic either
lower esophageal sphincter resting pressure does not
differ between the young and the elderly (Shaker
1993).
Esophageal dysmotility is one of the major reasons
for drug-induced esophagitis. Commonlyreported drugs
are NSAIDs, tetracycline derivates, potassium chloride,
and now also alendronate. Esophageal injury may be
related to acidic pH with some ofthese drugs. However,
potassium chloride causes injury by acting on smooth
muscles,particularly on the smallarteriole in the mucosa
and submucosa, thereby causing an ischemic lesion
which may lead to fibrosis and stricture. Such druginducedesophagitismaybeovercomeifthepatienttakes
precautions in terms of drinking before and after ingestion, and also to ingest in an upright position.
One common observation in the elderly is so-called
corkscrew esophagus. It has a very impressive radiologic appearance. It may or may not be symptomatic.
Control ofmotor activity in peristalsis in the esophagus
disease may cause strictures in the esophagus as frequently in the elderly as in younger patients. Key to
the diagnosis here is, of course, endoscopy, and also
double contrast examination. The history taking in
these patients must focus on other classic symptoms
or gastroesophageal reflux (Castell 1990; Fulp et al.
1990; Hey et al. 1982; Kikendall et al. 1983; McCord
and Clouse 1990; Semble et al. 1989; Siebens et al.
1986; Tucker et al. 1978).
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Voice and Dysphagia
https://t.me/med1917
Daniele Farneti
Contents
1 Introduction.............................................................. 176
2 Phylogenetic Development...................................... 176
2.1 Subglottic Pressure and Breathing............................ 177
2.2 Subglottic Pressure and Phonoarticulation ............... 177
2.3 Subglottic Pressure and Deglutition ......................... 179
3 Professional Voice Users......................................... 180
4 Common Physiological Events ............................... 180
4.1 Physical Adaptations in Artistic
Voice Production ....................................................... 180
5 Common Pathological Events ................................ 182
5.1 Vocal Alterations ....................................................... 182
5.2 Deglutition Alterations .............................................. 184
5.3 The Effects of Reflux................................................ 185
6 Recent Contributions in the Literature................ 185
References.......................................................................... 188
D. Farneti (&)
Voice and Swallowing Center,
‘‘Infermi’’ Hospital, Rimini, Italy
e-mail: lele_doc@libero.it
Abstract
The anatomical interaction between the upper
respiratory and digestive tracts conditions the
smooth running of their functions: breathing,
swallowing and voice articulation. The phylogenetic evolution of our species has rendered possible the optimum integration of these functions,
creating the conditions for an extremely refined
timing. This functional optimization has facilitated
the phonoarticulatory function with the possibility
of highly skilled aesthetic results, as in artistic
voice production. This anatomical integrity is
essential for a proper and optimal functioning.
Anatomical alteration may change a function, just
as a functional alteration may facilitate, in the
presence of comorbidity, anatomical changes. In
singing, for example, the physiological adjustments required to produce a more resonant voice
can alter, over time, the physiological characteristics of the structures involved in swallowing. The
lowering of the laryngotracheal axis, which facilitates the mechanisms of articulation and vocal
projection, may affect the timing of swallowing.
The pressures usually required in singing can
modify the functioning of the valves between the
chest and abdominal cavities. The chapter reviews
the main changes in the physiological and physiopathological characteristics of the upper respiratory and digestive tracts and the impact that artistic
vocal performances have on swallowing. Similar
considerations are made for other voice users. The
chapter concludes with a review of the literature on
the topic.
O. Ekberg (ed.), Dysphagia, Medical Radiology. Diagnostic Imaging, DOI: 10.1007/174_2011_341,
Ó Springer-Verlag Berlin Heidelberg 2012
175
176 D. Farneti
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1 Introduction
Under an anatomical and functional profile the
assessment of interactions between upper respiratory
and digestive tracts represents a field of great interest
(Laitman and Reindenberg 1993). According to the
natural indications derived from phylogenesis and
ontogenesis, the interaction between the respiratory
and digestive systems, in the head and neck, can
actually be evaluated almost completely and at the
various stages of life, including the intrauterine stage
(Wolfson and Laitman 1990). Upper airways can be
examined from the nostrils down to the cervicothoracic trachea and digestive pathways can be examined
from the oral cavity down to the duodenum. The
nasal–buccal–pharyngeal–laryngeal ‘‘apparatus’’ has
thus become the site of functions that can be clearly
identified: many actions and interactions can now be
viewed, even though they are still not completely
understood.
In the head and neck there are anatomically and
functionally integrated activities responsible for performing vital functions, such as breathing and swallowing and otherequally important non-vitalfunctions,
such as phonoarticulation. The phylogenetic evolution
of the head and neck has favoured phonation, which is
essential for the human species (differentiating it from
other, equally developed but non-verbal species), but
has penalized the other functions. So, if at birth the
newborn baby can be fed and breathe at the same time,
after the first monthsoflife, the maturationofthe larynx
separates the two functions.
In the course of millennia the possibility of verbal
communication has significantly fostered the evolution of our species, with an increasingly important
role of verbal production (Purves and Litchman
1985). Only over the last few decades has the intro-
duction of different communication modalities and
systems (e.g. the Internet) reduced or at least modified
the interest in such expression, typical of humans. The
use of voice as an expression mode is, however,
indispensable for various categories of operators,
either as an essential part of their everyday working
activity or because of its unique and powerful
expressive connotations. This is the case in those
professionals who use their voice while doing their
usual job duties (e.g. teachers, call centre operators,
telephonists, shop assistants, lawyers) or those who
co-morbidity
e
f
f
e
c
t
o
r
Fig. 1 Interaction among function, structure and comorbidity
breathing
deglutition
phono-articulation
f
u
n
c
t
i
o
n
use it according to ‘‘athletic’’ expressive modalities
(e.g. professional classical singers, actors).
As regards the intimate anatomical–functional
correlation between the head and neck, as mentioned
above, it is quite evident that the unusual employment
of the common effectors of breathing, swallowing and
phonoarticulation may cause disjoint or joint alterations of the functions they perform. The alteration of
such functions may, in the case of existing comorbidity conditions, result in openly pathological events,
in the same way as pathological events modify
functions (Fig. 1). A vicious cycle is started that may
involve both the effectors and the functions according
to subsequent and progressive levels of involvement.
The alteration of the fine balances of vocal athletic
exercises performed by vocal professionals may, for
instance, on the one hand, enhance the amplification
and capacity of sound, but, on the other, modify their
swallowing patterns. The alterations of these events
are such as to involve the artists’ emotional sphere,
making it more difficult for them to recover preexisting or modified balanced conditions.
2 Phylogenetic Development
A key element in the balance between respiration,
deglutition and phonoarticulation is the position of the
larynx inside the visceral space of the neck. In
mammals, the cervical rachis consists of seven vertebrae: the larynx is usually placed between the first
and the third cervical vertebra, with the epiglottis
behind the velum of the palate allowing a sort of
airway continuity (Soulié and Bardier 1907). In this
way the animal can breathe and at the same time
Voice and Dysphagia 177
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ingest food of various thicknesses. This high location
of the larynx, which is also found in human newborns,
as said above, strongly limits phonoarticulatory
capabilities: the pharyngeal cavity is extremely
reduced in size and consequently the tongue movements inside a relatively less wide cavity are limited.
The oral cavity, widened by the lip movements, acts
as a resonator for the laryngeal sound (Duchin 1990).
What happens in mammals occurs in the human
species in the first months of life. After the sixth
month, the larynx starts a descent that brings it to
the level of the fourth to seventh cervical vertebrae
(Kirchner 1993). This descent is accompanied by a
progressive decrease in cranial base angle that in
phylogenesis is found only in Homo sapiens (Negus
1949) and, in the development of our species, only
after the second year of life. When the epiglottis
leaves its narinal location, the child must be predisposed to swallowing in such a way as to protect
the lower airways during the passage of the bolus
into the pharynx. The laryngeal cavity opens up
inside the pharyngeal cavity, thereby imposing the
need for a sequential reconfiguration of the organ in
relation to what passes through it (breathing configuration, swallowing configuration) (Cook and
Kahrilas 1999). To facilitate the pharyngeal phase of
swallowing and further protect the lower airways,
the cervical region has increased its length so as to
allow a sufficiently safe deglutition timing and has
widened to enable the easy movement of structures
(Arensburg et al. 1989). With respect to the phonoarticulatory capacity, these various changes have
certainly represented a significant advantage. The
sounds produced in the larynx are amplified in a
series of wide and tortuous cavities (vocal tract) with
several varieties of harmonic filtering, whereas the
transit through the oral cavity allows a very fine
articulation thereof (Houghton 1993).
In the aerodigestive crossroads, the hyoid bone
plays an important role, since it acts as a kind of
balance arm suspended from the skull base, providing insertion to the muscles of the tongue and
subhyoid muscles, the suspensors of the laryngeal–
tracheal axis. The hyoid bone anchors the oral floor
to the cranial base, thereby optimizing the synchronization of the tongue movements with the
movement of the jaw and palate. Such movements
are important in breathing and phonoarticulation
(Lieberman 1979).
2.1 Subglottic Pressure and Breathing
Verbal production is a complex anatomofunctional
event that involves in parallel and in sequence several
organs and systems (Sataloff 1992). The central impulse activates a series of cortical and subcortical areas that act as regulators of muscle effectors
distributed in the organs involved to a different extent
in the phonoarticulatory function (Jurgens 1974;
Lotze et al. 2000).
The respiratory tract structures allow the movement of egressive airflow masses coming from the
lungs, after gas exchanges (haematosis) (Jaeger and
Matthys 1968). When the diaphragm, which is the
main inspiratory muscle, contracts, it increases the
size of the thoracic cavity. At the end of inspiration,
the diaphragm relaxes, and the elastic structures of the
chest return to a balanced state, thereby forcing out
the previously inhaled air volume and supplying
energy: under these circumstances the volumes (400–
500 ml) and the times of the two acts are equivalent.
However, the dynamics of the structures involved in
breathing for the purpose of phonation change.
During phonation, inspiration is shorter and expiration is substantially longer, with some interruptions
normally occurring during prosodic breaks within the
utterance. The air volumes mobilized are greater. The
inspiratory pressure and especially the expiratory
pressure against the closed glottis are much higher
and always require muscle activation. Fine adjustments are necessary to ensure the maintenance
of adequate pressure levels according to the acoustic characteristics of the articulated vocal emission
(Baken 1997).
2.2 Subglottic Pressure
and Phonoarticulation
The subglottic pressure ranges from 2–5 cm H2Oin
normal talking to 10–20 cm H
up to 50–60 cm H
O in singing. In thoracoabdominal
2
breathing, the rib movements and the lowering of the
diaphragm provide adequate air supply for any vocal
need. In the diaphragm–abdominal muscles antagonism (the abdominal muscles push and the diaphragm
remains in a state of tonic contraction) a precise
amount of expiratory flow and pressure generated
immediately below the vocal folds (subglottic
O in projected voice
2
178 D. Farneti
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Fig. 2 Interaction of
subglottic pressure between
respiration, deglutition and
phonation
Lung
volumes
BREATHING
DEGLUTITION
=
Larynx
LARYNGEAL
SPHINCTER
P subglottic
Subglottic Receptors
protected
Respiratory
phase
PHONATION
Pitch
Loudness
pressure) is achieved, according to the specific vocal
emission requirements (Fig. 2).
2.2.1 Laryngeal Sound
Sound is produced from the exhaled air at the level of
the vocal folds. Current theories and models suggested to explain such activity derive from Ewald’s
myoelastic theory (1898). The contributions of
Perello (1962), Hirano (1977), Dejonckère (1987) and
Van den Berg (1954) have led to the formulation of
the current myelastic aerodynamic theory of the vocal
fold vibration. According to this theory, the vibration
of vocal folds corresponds to the resolution of the
elastic conflict between the air pressure and the closure force of the vocal folds.
When the pressure of the subglottic air exceeds the
glottis resistance threshold, the vocal folds separate,
the air flows out through the glottis and the subglottic
pressure decreases. The vocal folds close back as
a result of elastic recoil and mechanical suction
(‘‘Bernoulli effect’’): a mucous wave is generated that
propagates from the inferior aspect of the vocal fold
down to the ventricle, reestablishing first glottis
resistance and then subglottic pressure. Cyclic
repetition of this mechanism takes place as long as
energy is available, resulting in the formation of air
Pharyngeal,
Suprahyoid
muscles
Oral cavity
Bolus:
chewing,
formation,
propulsion
OESOPHAGUS
Oesophagoglottic
reflex
Force, speed, duration
of muscle contraction
condensation and rarefaction areas in the glottis
(vibratory mechanical wave). The recurrence of the
event, in seconds, coincides with the fundamental
frequency of the subject’s voice.
The respiratory muscles may affect the fundamental frequency by regulating the subglottic pressure. The hyoid bone regulates the sagittal
movements of the larynx: usually larynx lowering is
observed during the production of low frequencies,
whereas larynx raising occurs for higher frequencies. Larynx lowering is associated with a backward
tilting of the thyroid cartilage with shortening,
decrease in tension and increase in the thickness of
the vocal folds, antagonizing the action of the
cricothyroid muscle. Larynx lowering (controlled by
subhyoid muscles) enhances low tones and lengthens the vocal tract.
The volume of the emitted sound is determined by
the amplitude of the ‘‘airflow variation’’ during
oscillation of the glottis. This variation is related both
to the subglottic pressure and to the amplitude of the
glottis movement. The ‘‘airflow’’ is the product of
the duct section (glottic surface) and the velocity of
the air outflow: the laryngeal muscles influence the
quality of the fold closure, whereas the respiratory
muscles regulate the subglottic pressure.
Voice and Dysphagia 179
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2.2.2 Articular Adaptation
The acoustic signal produced at the glottic level is a
complex, quasi-periodic sound, characterized by a
fundamental frequency, responsible for pitch perception, and by a series of harmonics at frequencies
that are multiples of the fundamental frequency
(Titze 1994). By passing through the supraglottic
cavities (vocal tract), the laryngeal sound undergoes
changes. The first change concerns the spectrum
and refers to the energy reinforcement of groups of
harmonics during their transit in a chamber, the
resonance frequency of which is closer to their
harmonic frequency. This energy reinforcement
generates the formants that are at the basis of
acoustic and perceptive recognition of the sound
produced by the speaker. Such modification takes
place in a passive way. The laryngeal sound can
also undergo active changes by passing inside the
vocal tract (Fant 1983). This occurs through the
production of aperiodic signals (noise) that replace
or are added to the glottic sound (periodic). Such
activity as a whole is referred to as articulation and
generates voiceless and voiced consonants, respectively: as a result thereof, consonants always have
an oral (noise) and a laryngeal (sound) source. The
sound of vowels, instead, has a laryngeal source,
since vowels are articulated in the oral cavity from
a mutual relationship of the tongue with the palate
and posterior (pharynx wall) and anterior (lips)
limiting structures.
2.3 Subglottic Pressure and Deglutition
Air under pressure, which is important in phonoarticulation-related mechanisms, plays an equally
important role in swallowing (Fig. 2). This occurs by
stimulating mechanoreceptors localized in the subglottic region of the larynx (Ardzakus and Wyke
1979). This type of receptor has been identified,
although the function of such receptors is not clearly
known (Widdicombe 1986). Patients who have had a
tracheotomy, for example, adequately ventilate;
therefore, the role of such receptors in breathing can be
considered as secondary. In addition to their function
in breathing and voice production, these receptors are
involved in swallowing. The stimulation of subglottic
receptors may possibly act as a signal for the central
nervous system that the larynx is ‘‘ready’’ (i.e. protected) for the bolus passage into the pharynx, and this
signal may, at the same time, influence the low motor
neurons of the brainstem innervating the pharynx.
The precise coordination of the respiratory and
digestive systems is crucial in safe swallowing and
this is reflected in the closed topographic organization of respiratory, deglutitory and branchial motor
neurons (Larson et al. 1994). The localization,
function and interaction of these neurons support the
theory of an ‘‘online’’ processing of peripheral afferences both at a cortical and at a low brainstem
level (Maddock and Gilbert 1993). As a result of the
neuroanatomical connection between subglottic
receptors and branchial motor neurons for the
pharynx and larynx, the feedback from subglottic
receptors may presumably affect the recruitment of
motor neurons in the brainstem capable of activating
the pharyngeal muscles during swallowing so that
the force, speed and duration of the muscular contraction are regulated (normalized) by the closing of
the larynx. The stimulation of this reflex arc
increases the number of pharyngeal motor neurons,
which, in turn, mediate a higher speed of the bolus
transit, decreased time of pharyngeal contraction
(resulting in a quicker pharyngeal clearing) and a
stronger muscular contraction.
This feed-forward system may detect that a sensory input (subglottic pressure) has not been received
and control a function (swallowing) by increasing the
cortical processing, thereby ensuring safe passage of
the bolus into the oesophagus. Cortical processing
would thus account for a prolonged muscular contraction (Diez Gross et al. 2003).
Another possibility is that the segmental reflex is
involved in bolus propulsion and therefore without
said reflex the bolus is propelled more slowly. In
this way, the pharyngeal muscles may increase the
time of their contraction as a result of the increased
latency of the bolus transit. This would partly
explain why swallowing occurs in the later part of
expiration. Swallowing during expiration helps the
lungs fill with air before swallowing and it might be
necessary to maximize the subglottic pressure and
subsequent swallowing. In this way air is removed
from the pharynx (thereby reducing air ingestion)
and the exit of the bolus from the airways into the
oesophagus is facilitated (Nishino et al. 1985).
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benign cordal lesions, nodules, haemorrhage and cysts
3 Professional Voice Users
All those who use their voice within their professional
activity may be deemed as voice professionals. This
term makes us initially think of singers, actors or
broadcasters, that is professionals who rely or have
relied on their voice for their popularity or career. A
wide variety of professional operators use their voice
in their occupations: teachers, ecclesiastics, lawyers,
telemarketers, receptionists and servicemen are just a
few of the groups of people for whom oral communication is an essential part of their job. Then there are
of course physicians, managers, call centre operators
and many others. Although we live in the Internet and
e-mail era, we can hardly imagine these professionals
without an adequate voice for their professional tasks.
In daily clinical phoniatric practice, however,
voice disorders are also observed in housewives
(Baitha et al. 2002).
Voice professionals can be divided into three main
categories: top performers, such as opera singers, for
whom any minimal voice alteration may sometimes
have disastrous consequences; vocalists, including
most other singers and actors; and finally all the other
professionals mentioned above.
Workers who rely on their voice as an essential
part of their occupation range from 25 to 35% of
employees in the USA (Titze et al. 1997) and in other
industrialized countries (Vilkman 2000) The professionals who are mostly affected by voice problems are
teachers, with an incidence ranging from 38 (Smith
et al. 1998) to 80% (Sapir et al. 1993), followed by
telemarketers (68%) (Jones et al. 2002), aerobics
instructors (44%) (Long et al. 1998) and salesmen
(about 4%) (Coyle et al. 2001).
Among the 2,286 dysphonic patients reported by
Brodnitz ( 1971), in 80%, dysphonia was due to vocal
abuse or psychogenic factors causing dysfunction. Of
these patients, 20% had organic lesions that in women
were caused in 15% of cases by endocrine alterations.
Other frequent causes were infectious laryngitis and
reflux laryngitis.
Professional voice users complain of several
problems, including hoarseness, vocal breaks, voice
loss, hypophonia and vocal fatigue. Correlated
symptoms may be phonatory dyspnoea, dry throat or
sore throat, constricted sensation and pain. Chronic
voice problems may be due to laryngitis and oedemas,
(Wingate et al. 2007).
4 Common Physiological Events
From the considerations illustrated in the previous
sections, it appears evident that the respiratory,
deglutitory, and phonoarticulatory functions are closely integrated and such integration resides in the
integrity of the structures performing these functions.
4.1 Physical Adaptations in Artistic
Voice Production
In singing, especially without amplification (classical
or lyrical singing), the professional singer needs to
exert greater pressures and maintain them for longer
periods as compared with the pressures used in normal speech production. The need to obtain a product
with a richer timbre (amplification) and carrying
greater energy requires mutual adjustments of both
the breathing dynamics and the vocal tract (Titze
1994). There is actually the need to realize a wider
filtering resonating chamber while keeping the pressures at the lowest possible levels. This is achieved by
lowering the larynx and the tongue and through a
wider opening of the mouth. The forced and persistent
lowering and anchoring of the larynx implies the
downward movement of all related structures: hyoid
bone and tongue root, with a strongly arched and
raised soft palate. In romantic vocal productions all
this goes to the benefit of the volume but to the detriment of articulatory capabilities and voice colouring
that were so much appreciated in the previous musical
period (Baroque).
As already said, in costal diaphragmatic breathing,
during inspiration, the diaphragm contracts and the
thoracic cavity becomes wider in its vertical and
transverse diameters. During expiration, the breathing
phase during which speech production and singing
occur, the diaphragm is totally inactive and its
rising is regulated only by other respiratory muscles
(abdominal muscles, intercostal muscles, etc.).
According to the need of producing low-intensity or
high-intensity tones, high-pitched or low-pitched
tones, or filatura, the behaviour of the respiratory
muscles will affect the breathing dynamics. When full
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volume is reached, the elastic retraction forces of the
lungs will spontaneously tend to empty them (as
happens during quiet breathing). For most singing
requirements, such retraction forces produce a subglottic air pressure that needs to be adjusted to the
intensity of the sound to be emitted. A force capable
of contrasting the elastic forces and reducing the subcordal pressure is therefore needed upon the attack of
the sound, with an excessive impact on the vocal folds
(brusque attack). This is what singers call ‘‘appoggio’’:
the thorax is held in position by the action of external
intercostal muscles, whereas the abdominal wall
supports this activity. During a musical phrase, in
order to keep the desired air pressure, the diaphragm
starts rising, accompanied by a contraction of the
abdominal muscles that provide the ‘‘support’’, which
is constantly sought by the singer (Fussi 2003).
4.1.1 Valvular Activities
In these dynamics, diaphragm behaviour should be
considered as an antireflux mechanism. Nowadays, it
is clear that both the smooth muscle of the distal
oesophagus (lower oesophageal sphincter) and the
pillars of the diaphragm (crural diaphragm) represent
the distal protection mechanisms of the oesophagus
(Mittal and Balaban 1997). Changes in distal
oesophageal pressures are correlated to contractions
of the oesophagus and stomach (Dent et al. 1983),
whereas crural contractions are related to the amount
of inspiration or to the performing of activities
increasing intra-abdominal pressure (e.g. Valsalva
manoeuvre, cough, defecation, delivery) (Mittal et al.
1990): this mechanism is much more dynamic, pow-
erful and effective in guaranteeing containment to the
lower oesophageal sphincter. Furthermore, when the
intra-abdominal pressure increases, a reflex is generated that causes crural contraction and an increase in
the lower oesophageal sphincter pressure (Shafik et al.
2004). The crura, however, consist of easily fatigable
striated muscle fibres that are therefore inadequate for
prolonged or too fast performances, which are quite
often required in singing, for instance in supporting
prolonged and sustained musical phrases or vocal
exercises at extreme pitches. The air compression
generated in the rib cage by the push action of the
abdominal muscles and by the lowering of the sternum increases the expiratory push but compresses
the stomach, antagonizing the lower oesophageal
sphincter. These dynamics may also account for the
PATHOPHYSIOLOGICAL EVENTS
UES failure UES dysfunction
increased pressure in the pharynx
- dorsal or lateral pharyngeal
pouches
- diverticula
Fig. 3 Direct contact of refluxate with laryngeal structures.
UES upper oesophageal sphincter
hyoid bone
-pharyngeal
inflammation
- oesophageal
inflammation
-webs
lack of protection
- refluxate penetration
- laryngeal
aspiration/penetration
pharynx
cricopharyngeus m
+
agonist
antagonist
Fig. 4 Indirect involvement of laryngeal structure
larynx
increase in high-reflux episodes up into the pharynx
during physical activity (Emerenziani et al. 2005)or
with increased intra-abdominal pressure. Under these
conditions there might be a direct contact of the
refluxate with the laryngeal structures (direct mechanism) (Fig. 3), which can also occur by means of a
Distal reflux through the lower oesophageal
sphincter causes, through a neural or neurohumoral
transmission route, a dysfunction in the upper
oesophageal sphincter which may result in a reduced
-
oesophagus
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