Effects of HCl-pepsin laryngeal instillations on upper airway patency-maintaining mechanisms

1998 ◽  
Vol 84 (4) ◽  
pp. 1299-1304 ◽  
Author(s):  
Franca B. Sant’Ambrogio ◽  
Giuseppe Sant’Ambrogio ◽  
Kyungsoon Chung
Keyword(s):  
Gastroesophageal Reflux ◽  
Negative Pressure ◽  
Sensory Feedback ◽  
Upper Airway ◽  
Esophageal Pressure ◽  
Airway Patency ◽  
Laryngeal Mucosa ◽  
Posterior Cricoarytenoid Muscle ◽  
Anesthetized Dogs ◽  
Posterior Cricoarytenoid

Gastroesophageal reflux has been indicated as an etiopathological factor in disorders of the upper airway. Upper airway collapsing pressure stimulates pressure-responsive laryngeal receptors that reflexly increase the activity of upper airway abductor muscles. We studied, in anesthetized dogs, the effects of repeated laryngeal instillations of HCl-pepsin (HCl-P; pH = 2) on the response of laryngeal afferent endings and the posterior cricoarytenoid muscle (PCA) to negative pressure. The effect of negative pressure on receptor discharge or PCA activity was evaluated by comparing their response to upper airway (UAO) and tracheal occlusions (TO). It is only during UAO, but not during TO, that the larynx is subjected to negative transmural pressure. HCl-P instillation decreased the rate of discharge during UAO of the 10 laryngeal receptors studied from 56.4 ± 10.9 (SE) to 38.2 ± 9.2 impulses/s ( P < 0.05). With UAO, the peak PCA moving time average, normalized by dividing it by the peak values of esophageal pressure, decreased after six HCl-P trials from 4.29 ± 0.31 to 2.23 ± 0.18 ( n = 6; P < 0.05). The responses to TO of either receptors or PCA remained unaltered. We conclude that exposure of the laryngeal mucosa to HCl-P solutions, as it may occur with gastroesophageal reflux, impairs the patency-maintaining mechanisms provided by laryngeal sensory feedback. Inflammatory and necrotic alterations of the laryngeal mucosa are likely responsible for these effects.

Laryngeal influences on breathing pattern and posterior cricoarytenoid muscle activity

1985 ◽  
Vol 58 (4) ◽  
pp. 1298-1304 ◽  
Author(s):  
F. B. Sant'Ambrogio ◽  
O. P. Mathew ◽  
W. D. Clark ◽  
G. Sant'Ambrogio
Keyword(s):  
Breathing Pattern ◽  
Upper Airway ◽  
Airway Patency ◽  
Airway Occlusion ◽  
Laryngeal Nerves ◽  
Relative Contribution ◽  
Posterior Cricoarytenoid Muscle ◽  
Regulation Of Breathing ◽  
Anesthetized Dogs ◽  
Posterior Cricoarytenoid

Receptors responding to transmural pressure, airflow, and contraction of laryngeal muscles have been previously identified in the larynx. To assess the relative contribution of these three types of receptors to the reflex changes in breathing pattern and upper airway patency, we studied diaphragmatic (DIA) and posterior cricoarytenoid muscle (PCA) activity in anesthetized dogs during spontaneous breathing and occluded efforts with and without bypassing the larynx. Inspiratory duration (TI) was longer, mean inspiratory slope (peak DIA/TI) was lower, and PCA activity was greater with upper airway occlusion than with tracheal occlusion (larynx bypassed). Bilateral section of the superior laryngeal nerves eliminated these differences. When respiratory airflow was diverted from the tracheostomy to the upper airway the only change attributable to laryngeal afferents was an increase in PCA activity. These results confirm the importance of the superior laryngeal nerves in the regulation of breathing pattern and upper airway patency and suggest a prevalent role for laryngeal negative pressure receptors.

Respiratory motor nerve activities during spontaneous bladder contractions

1994 ◽  
Vol 77 (3) ◽  
pp. 1349-1354 ◽  
Author(s):  
M. J. Gdovin ◽  
S. L. Knuth ◽  
D. Bartlett
Keyword(s):  
Hypoglossal Nerve ◽  
Motor Nerve ◽  
Upper Airway ◽  
Respiratory Response ◽  
Airway Patency ◽  
Pelvic Nerves ◽  
Initial Decrease ◽  
Posterior Cricoarytenoid ◽  
Increased Activity ◽  
Nerve Discharge

We monitored spontaneous bladder contractions (SBCs) in decerebrate vagotomized paralyzed ventilated cats while recording respiratory motor nerve activities and intravesical pressure under isovolumetric conditions. Phrenic nerve discharge diminished during SBCs, as did the activities of the hypoglossal nerve, the nasolabial branch of the facial nerve, and inspiratory (posterior cricoarytenoid) and expiratory (thyroarytenoid) branches of the recurrent laryngeal nerve. Hypoglossal activity was most strikingly reduced during SBCs, disappearing completely in some animals. The triangularis sterni nerve exhibited an initial decrease, followed by an increase in activity during SBCs, whereas the cranial iliohypogastric nerve showed increased activity. The changes in nerve activities during SBCs could also be elicited by passive distension of the bladder and were abolished by bilateral section of the pelvic nerves. These findings extend the understanding of reflexes originating from the urinary bladder to include a coordinated respiratory response and suggest that these reflexes may compromise upper airway patency under some conditions.

Control of respiratory activity of the genioglossus muscle in micrognathic infants

1986 ◽  
Vol 61 (4) ◽  
pp. 1523-1533 ◽  
Author(s):  
J. L. Roberts ◽  
W. R. Reed ◽  
O. P. Mathew ◽  
B. T. Thach
Keyword(s):  
Upper Airway ◽  
Esophageal Pressure ◽  
Progressive Increase ◽  
Emg Activity ◽  
Nasal Breathing ◽  
Airway Patency ◽  
Tongue Muscle ◽  
Airway Occlusion ◽  
Pharyngeal Airway ◽  
Obstructive Sleep

The genioglossus (GG) muscle activity of four infants with micrognathia and obstructive sleep apnea was recorded to assess the role of this tongue muscle in upper airway maintenance. Respiratory air flow, esophageal pressure, and intramuscular GG electromyograms (EMG) were recorded during wakefulness and sleep. Both tonic and phasic inspiratory GG-EMG activity was recorded in each of the infants. On occasion, no phasic GG activity could be recorded; these silent periods were unassociated with respiratory embarrassment. GG activity increased during sigh breaths. GG activity also increased when the infants spontaneously changed from oral to nasal breathing and, in two infants, with neck flexion associated with complete upper airway obstruction, suggesting that GG-EMG activity is influenced by sudden changes in upper airway resistance. During sleep, the GG-EMG activity significantly increased with 5% CO2 breathing (P less than or equal to 0.001). With nasal airway occlusion during sleep, the GG-EMG activity increased with the first occluded breath and progressively increased during the subsequent occluded breaths, indicating mechanoreceptor and suggesting chemoreceptor modulation. During nasal occlusion trials, there was a progressive increase in phasic inspiratory activity of the GG-EMG that was greater than that of the diaphragm activity (as reflected by esophageal pressure excursions). When pharyngeal airway closure occurred during a nasal occlusion trial, the negative pressure at which the pharyngeal airway closed (upper airway closing pressure) correlated with the GG-EMG activity at the time of closure, suggesting that the GG muscle contributes to maintaining pharyngeal airway patency in the micrognathic infant.

Nasal and laryngeal reflex responses to negative upper airway pressure

1984 ◽  
Vol 56 (3) ◽  
pp. 746-752 ◽  
Author(s):  
E. van Lunteren ◽  
W. B. Van de Graaff ◽  
D. M. Parker ◽  
J. Mitra ◽  
M. A. Haxhiu ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Moving Average ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Laryngeal Nerve ◽  
Topical Anesthesia ◽  
Inspiratory Activity ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles

The effects of negative pressure applied to just the upper airway on nasal and laryngeal muscle activity were studied in 14 spontaneously breathing anesthetized dogs. Moving average electromyograms were recorded from the alae nasi (AN) and posterior cricoarytenoid (PCA) muscles and compared with those of the genioglossus (GG) and diaphragm. The duration of inspiration and the length of inspiratory activity of all upper airway muscles was increased in a graded manner proportional to the amount of negative pressure applied. Phasic activation of upper airway muscles preceded inspiratory activity of the diaphragm under control conditions; upper airway negative pressure increased this amount of preactivation. Peak diaphragm activity was unchanged with negative pressure, although the rate of rise of muscle activity decreased. The average increases in peak upper airway muscle activity in response to all levels of negative pressure were 18 +/- 4% for the AN, 27 +/- 7% for the PCA, and 122 +/- 31% for the GG (P less than 0.001). Rates of rise of AN and PCA electrical activity increased at higher levels of negative pressure. Nasal negative pressure affected the AN more than the PCA, while laryngeal negative pressure had the opposite effect. The effects of nasal negative pressure could be abolished by topical anesthesia of the nasal passages, while the effects of laryngeal negative pressure could be abolished by either topical anesthesia of the larynx or section of the superior laryngeal nerve. Electrical stimulation of the superior laryngeal nerve caused depression of AN and PCA activity, and hence does not reproduce the effects of negative pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Specificity of esophageal electrode recordings of posterior cricoarytenoid muscle activity

1989 ◽  
Vol 66 (3) ◽  
pp. 1501-1505 ◽  
Author(s):  
G. Insalaco ◽  
G. Sant'Ambrogio ◽  
F. B. Sant'Ambrogio ◽  
S. T. Kuna ◽  
O. P. Mathew
Keyword(s):  
Marked Decrease ◽  
Upper Airway ◽  
Emg Activity ◽  
Small Reduction ◽  
Posterior Cricoarytenoid Muscle ◽  
Intramuscular Electrodes ◽  
Inspiratory Activity ◽  
Recorded Activity ◽  
Posterior Cricoarytenoid ◽  
The Right

Esophageal electrodes have been used for recording the electromyographic (EMG) activity of the posterior cricoarytenoid muscle (PCA). To determine the specificity of this EMG technique, esophageal electrode recordings were compared with intramuscular recordings in eight anesthetized mongrel dogs. Intramuscular wire electrodes were placed in the right and left PCA, and the esophageal electrode was introduced through the nose or mouth and advanced into the upper esophagus. On direct visualization of the upper airway, the unshielded catheter electrode entered the esophagus on the right or left side. Cold block of the recurrent laryngeal nerve (RLN) ipsilateral to the esophageal electrode was associated with a marked decrease in recorded activity, whereas cold block of the contralateral RLN resulted only in a small reduction in activity. After supplemental doses of anesthesia were administered, bilateral RLN cold block essentially abolished the activity recorded with the intramuscular electrodes as well as that recorded with the esophageal electrode. Before supplemental doses of anesthesia were given, especially after vagotomy, the esophageal electrode, and in some cases the intramuscular electrodes, recorded phasic inspiratory activity not originating from the PCA. Therefore, one should be cautious in interpreting the activity recorded from esophageal electrodes as originating from the PCA, especially in conditions associated with increased respiratory efforts.

Thoracic influence on upper airway patency

1988 ◽  
Vol 65 (5) ◽  
pp. 2124-2131 ◽  
Author(s):  
W. B. Van de Graaff
Keyword(s):  
Muscle Activity ◽  
Upper Airway ◽  
Constant Flow ◽  
Airway Patency ◽  
Anesthetized Dogs ◽  
Measured Resistance ◽  
Flow Through ◽  
Phrenic Nerves ◽  
Tracheostomy Tubes ◽  
Spontaneously Breathing

Patency of the upper airway (UA) is usually considered to be maintained by the activity of muscles in the head and neck. These include cervical muscles that provide caudal traction on the UA. The thorax also applies caudal traction to the UA. To observe whether this thoracic traction can also improve UA patency, we measured resistance of the UA (RUA) during breathing in the presence and absence of UA muscle activity. Fifteen anesthetized dogs breathed through tracheostomy tubes. RUA was calculated from the pressure drop of a constant flow through the isolated UA. RUA decreased 31 +/- 5% (SEM) during inspiration. After hyperventilating seven of these dogs to apnea, we maximally stimulated the phrenic nerves to produce paced diaphragmatic breathing. Despite absence of UA muscle activity, RUA fell 51 +/- 11% during inspiration. Graded changes were produced by reduced stimulation. In six other dogs we denervated all UA muscles. RUA still fell 25 +/- 7% with inspiration in these spontaneously breathing animals. When all caudal ventrolateral cervical structures mechanically linking the thorax to the UA were severed, RUA increased and respiratory fluctuations ceased. These findings indicate that tonic and phasic forces generated by the thorax can improve UA patency. Inspiratory increases in UA patency cannot be attributed solely to activity of UA muscles.

scholarly journals Suppression of Thyroarytenoid Muscle Responses during Repeated Air Pressure Stimulation of the Laryngeal Mucosa in Awake Humans

2005 ◽  
Vol 114 (4) ◽  
pp. 264-270 ◽  
Author(s):  
Pamela Reed Kearney ◽  
Eric A. Mann ◽  
Christopher J. Poletto ◽  
Christy L. Ludlow
Keyword(s):  
Air Pressure ◽  
Repeated Presentation ◽  
Repeated Stimulation ◽  
Laryngeal Mucosa ◽  
Posterior Cricoarytenoid Muscle ◽  
Interstimulus Intervals ◽  
Posterior Cricoarytenoid ◽  
Muscle Responses ◽  
Thyroarytenoid Muscle ◽  
Stimulation Of

Repeated stimulation of the laryngeal mucosa occurs during speech. Single stimuli, however, can elicit the laryngeal adductor response (LAR). Our hypothesis was that the LAR to repeated rapid air pressure stimuli is centrally suppressed in humans. Hookedwire electrodes were inserted into the thyroarytenoid and cricothyroid muscles on both sides and into the posterior cricoarytenoid muscle on one side. Pairs of air puff stimuli were presented to the mucosa over the arytenoids at pressure levels three times threshold with interstimulus intervals from 250 to 5,000 ms. Bilateral thyroarytenoid responses occurred at around 150 ms to more than 70% of the initial stimuli. With repeated presentation at intervals of 2 seconds or less, the percent occurrence decreased to less than 40% and response amplitudes were reduced by 50%. Central suppression of adductor responses to repeated air puff stimuli may allow speakers to produce voice without eliciting reflexive spasms that could disrupt speech.

scholarly journals Differential effects of acute cerebellectomy on cough in spontaneously breathing cats

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253060
Author(s):  
M. Nicholas Musselwhite ◽  
Tabitha Y. Shen ◽  
Melanie J. Rose ◽  
Kimberly E. Iceman ◽  
Ivan Poliacek ◽  
...  
Keyword(s):  
Motor Behavior ◽  
Motor Pattern ◽  
Respiratory Muscles ◽  
Upper Airway ◽  
Esophageal Pressure ◽  
Adductor Muscle ◽  
Motor Drive ◽  
Mechanical Stimuli ◽  
Posterior Cricoarytenoid ◽  
Spontaneously Breathing

The role of the cerebellum in controlling the cough motor pattern is not well understood. We hypothesized that cerebellectomy would disinhibit motor drive to respiratory muscles during cough. Cough was induced by mechanical stimulation of the tracheobronchial airways in anesthetized, spontaneously breathing adult cats (8 male, 1 female), and electromyograms (EMGs) were recorded from upper airway, chest wall, and abdominal respiratory muscles. Cough trials were performed before and at two time points after total cerebellectomy (10 minutes and >1 hour). Unlike a prior report in paralyzed, decerebrated, and artificially ventilated animals, we observed that cerebellectomy had no effect on cough frequency. After cerebellectomy, thoracic inspiratory muscle EMG magnitudes increased during cough (diaphragm EMG increased by 14% at 10 minutes, p = 0.04; parasternal by 34% at 10 minutes and by 32% at >1 hour, p = 0.001 and 0.03 respectively). During cough at 10 minutes after cerebellectomy, inspiratory esophageal pressure was increased by 44% (p = 0.004), thyroarytenoid (laryngeal adductor) muscle EMG amplitude increased 13% (p = 0.04), and no change was observed in the posterior cricoarytenoid (laryngeal abductor) EMG. Cough phase durations did not change. Blood pressure and heart rate were reduced after cerebellectomy, and respiratory rate also decreased due to an increase in duration of the expiratory phase of breathing. Changes in cough-related EMG magnitudes of respiratory muscles suggest that the cerebellum exerts inhibitory control of cough motor drive, but not cough number or phase timing in response to mechanical stimuli in this model early after cerebellectomy. However, results varied widely at >1 hour after cerebellectomy, with some animals exhibiting enhancement or suppression of one or more components of the cough motor behavior. These results suggest that, while the cerebellum and behavior-related sensory feedback regulate cough, it may be difficult to predict the nature of the modulation based on total cerebellectomy.

Coordination between Palatal and Laryngeal Muscle Activities in Response to Rebreathing and Lung Inflation

1996 ◽  
Vol 33 (6) ◽  
pp. 459-462 ◽  
Author(s):  
Hidehiko Koizumi ◽  
Mikihiko Kogo ◽  
Tokuzo Matsuya
Keyword(s):  
Upper Airway ◽  
Adductor Muscle ◽  
The Other ◽  
Sodium Pentobarbital ◽  
Abductor Muscle ◽  
Lung Inflation ◽  
Laryngeal Muscle ◽  
Levator Veli Palatini ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid

The soft palate and larynx play an important role in respiration and phonation, regulating the airflow in the upper airway. The levator veli palatini muscle (LVP) is the principal muscle responsible for generating palatal movements. The lateral cricoarytenoid muscle (LCA) is a laryngeal adductor muscle, and the posterior cricoarytenoid muscle (PCA) is a laryngeal abductor muscle. This study was designed to define, by electromyographic techniques, the coordination between palatal and laryngeal muscle activities in response to rebreathing and lung inflation. We performed tracheotomies on 12 mongrel dogs anesthetized with sodium pentobarbital and compared the effects of rebreathing and lung inflation on LVP activities with those on LCA and PCA activities. During rebreathing, expiratory LVP and inspiratory PCA activities were progressively augmented, but expiratory LCA activity was inhibited. On the other hand, lung inflation caused augmentation of LVP and LCA activities. In contrast, lung inflation inhibited PCA activity. We thus concluded that LVP activity coordinates with PCA activity in response to alternation of Paco2 and Pao2 levels, while it coordinates with LCA activity in response to lung inflation.

scholarly journals Modulation of laryngeal and respiratory pump muscle activities with upper airway pressure and flow

2001 ◽  
Vol 91 (2) ◽  
pp. 897-904 ◽  
Author(s):  
M. H. Stella ◽  
S. J. England
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Upper Airway ◽  
Abdominal Muscle ◽  
Positive Pressure ◽  
Emg Activity ◽  
Posterior Cricoarytenoid ◽  
Spontaneously Breathing ◽  
Respiratory Muscle Activity ◽  
Stimulation Of

The hypothesis that upper airway (UA) pressure and flow modulate respiratory muscle activity in a respiratory phase-specific fashion was assessed in anesthetized, tracheotomized, spontaneously breathing piglets. We generated negative pressure and inspiratory flow in phase with tracheal inspiration or positive pressure and expiratory flow in phase with tracheal expiration in the isolated UA. Stimulation of UA negative pressure receptors with body temperature air resulted in a 10–15% enhancement of phasic moving-time-averaged posterior cricoarytenoid electromyographic (EMG) activity above tonic levels obtained without pressure and flow in the UA (baseline). Stimulation of UA positive pressure receptors increased phasic moving-time-averaged thyroarytenoid EMG activity above tonic levels by 45% from baseline. The same enhancement of posterior cricoarytenoid or thyroarytenoid EMG activity was observed with the addition of flow receptor stimulation with room temperature air. Tidal volume and diaphragmatic and abdominal muscle activity were unaffected by UA flow and/or pressure, whereas respiratory timing was minimally affected. We conclude that laryngeal afferents, mainly from pressure receptors, are important in modulating the respiratory activity of laryngeal muscles.

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