Respiratory Activity of the Vocal Cords in Normal Subjects and Patients with Airflow Obstruction: An Electromyographic Study

1981 ◽  
Vol 61 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Julia Payne ◽  
T. Higenbottam ◽  
G. Guindi
Keyword(s):  
Respiratory Activity ◽  
Airflow Obstruction ◽  
Respiratory Muscles ◽  
Normal Subjects ◽  
Electromyographic Activity ◽  
Surface Electrode ◽  
Vocal Cords ◽  
Phasic Activity ◽  
Voluntary Hyperventilation ◽  
Inspiratory Activity

1. A surface electrode was used to record electromyographic activity of the posterior crico-arytenoid muscle during breathing in normal subjects and patients with airflow obstruction. 2. Phasic activity of the posterior crico-arytenoid muscle was demonstrated. This was present on inspiration and absent on expiration. 3. Phasic inspiratory activity in normal subjects was present only during periods of voluntary hyperventilation, increasing with tidal volume, whereas in patients with airflow obstruction inspiratory activity was present even during resting breathing and failed to increase further during voluntary hyperventilation. 4. The posterior crico-arytenoid muscle may be considered as an inspiratory muscle acting analogously to other accessory respiratory muscles.

Effect of posture, route of respiration, and negative pressure on palatal muscle activity in humans

1995 ◽  
Vol 79 (2) ◽  
pp. 448-454 ◽  
Author(s):  
I. L. Mortimore ◽  
R. Mathur ◽  
N. J. Douglas
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Respiratory Activity ◽  
Maximum Activity ◽  
Electromyographic Activity ◽  
Airway Narrowing ◽  
Pressure Application ◽  
Supine Posture ◽  
Inspiratory Activity ◽  
Male Subjects

Sleep apnea is worse in the supine posture and is associated with retropalatal airway narrowing or occlusion. We have, therefore, examined the effects of posture, negative pressure, and route of respiration on palatal muscle activity in 13 nonsnoring awake male subjects by using electromyography. Electromyographic activity of the levator palatini and palatoglossus was expressed as a percentage of maximum activity. Both the levator palatini (P = 0.002) and palatoglossus (P = 0.002) exhibited phasic inspiratory activity. Overall, posture did not affect the levator palatini (F = 1.58; P = 0.23) or palatoglossus (F = 0.98; P = 0.34) activity, but analysis by route of respiration showed the palatoglossus to be more active when the subjects were nose breathing supine (F = 6.64; P = 0.02). Levator palatini activity was lower when nose breathing was compared with mouth breathing in both the erect and supine postures (F = 6.67; P < 0.02). Nose breathing with the mouth held open caused an increase in palatoglossal activity (P = 0.04). Negative-pressure application (0 to -12.5 cmH2O) caused significant increases in levator palatini (P < 0.001) and palatoglossus (P < 0.001) activity, 100 ms after pressure stimulus, irrespective of route. However, the palatoglossus required significantly greater negative pressures to cause activation when applied via the nose compared with the mouth (P < 0.05). These observations indicate that the levator palatini and palatglossus have respiratory activity and are reflexly activated by negative pressure.

Respiratory movements of the vocal cords

1983 ◽  
Vol 54 (5) ◽  
pp. 1269-1276 ◽  
Author(s):  
T. Brancatisano ◽  
P. W. Collett ◽  
L. A. Engel
Keyword(s):  
Lung Volume ◽  
Respiratory Control ◽  
Respiratory Muscles ◽  
Normal Subjects ◽  
Tight Coupling ◽  
Tidal Breathing ◽  
Vocal Cords ◽  
Residual Capacity ◽  
The Relationship ◽  
Respiratory Movements

We examined the movements of the vocal cords during tidal breathing, panting, and large changes in lung volume in 12 normal subjects. The glottis was observed with a fiber-optic bronchoscope, and the glottic image was recorded together with flow, volume, and a time marker onto videotape. Phasic respiratory swings in glottic width (dg) and glottic area (Ag) were reproducible in all subjects but differed substantially between subjects. In the group as a whole dg and Ag increased during inspiration to 10.1 +/- 5.6 mm and 126 +/- 8 mm2 (mean +/- SE), respectively, whereas during expiration the lowest values were 5.7 +/- 0.5 mm and 70 +/- 7 mm2, respectively. These extreme dimensions corresponded closely to the midtidal volume points in the respiratory cycle. Glottic width during vital capacity (VC) expirations was nearly 30% greater at a flow of 1.2 l/s than at 0.5 l/s, but the relationship between dg and lung volume differed between subjects. When swings in dg were minimized by panting, there was no difference in dg between functional residual capacity (FRC) and a volume corresponding to midinspiratory capacity. However, tidal breathing at this lung volume was associated with a 20% decrease in dg compared with breathing at FRC. Our observations indicate a tight coupling between the pattern of glottic movement and the respiratory volume cycle. The results suggest that during voluntary respiratory maneuvers both intrinsic laryngeal and respiratory muscles are recruited, participating as effector organs in ventilatory and respiratory control.

Neuromechanical regulation of respiratory motor output in ventilator-dependent C1-C3 quadriplegics

1995 ◽  
Vol 79 (1) ◽  
pp. 312-323 ◽  
Author(s):  
P. M. Simon ◽  
A. M. Leevers ◽  
J. L. Murty ◽  
J. B. Skatrud ◽  
J. A. Dempsey
Keyword(s):  
Mechanical Ventilation ◽  
Muscle Activity ◽  
Normal Subjects ◽  
Inspiratory Muscle ◽  
Phasic Activity ◽  
Cord Injury ◽  
Inhibitory Feedback ◽  
Dependent Inhibition ◽  
Inspiratory Activity ◽  
End Tidal

To evaluate the role of phrenic and sternocleidomastoid afferents as alternate sources of inhibitory feedback during mechanical ventilation, we studied five C2-C3 quadriplegics with sensory denervation of the rib cage and diaphragm, six C1-C2 quadriplegics with additional loss of sensory feedback from the neck muscles, and seven normal subjects. We compared the return of inspiratory muscle activity [the recruitment threshold (PCO2RT)] during mechanical ventilation between subject groups after stepwise increases in end-tidal PCO2 (PETCO2) either by increasing the inspired fraction of CO2 (FICO2), decreasing tidal volume (VT; 50 ml/min), or decreasing frequency (f; 1 breath/2 min). Normal subjects were mechanically hyperventilated via a nasal mask until inspiratory activity was undetectable. Efferent input to the sternocleidomastoid was intact at both levels of spinal cord injury, but phasic activity was not evident at the quadriplegics' baseline resting ventilation. The PCO2RT was defined as the level of PETCO2 at which phasic activity of the diaphragm in normal subjects and of the sternocleidomastoid in C1-C2 and C2-C3 quadriplegics recurred. The mean PCO2RT (in response to raising PETCO2 via increased FICO2 while maintaining a high VT and f) was not significantly different (P = 0.6) between normal subjects (43 +/- 3 Torr) and C2-C3 quadriplegics (38 +/- 5 Torr). Both subject groups demonstrated a frequency- and volume-related inhibition, as evidenced by a substantially lower PCO2RT when PETCO2 was raised by reducing either VT or f. In contrast to the C2-C3 quadriplegics, the C1-C2 quadriplegics responded with a similar PCO2RT among the three different mechanical ventilation trials, independent of whether PETCO2 was raised with high VT and f, with reduced VT, or with reduced f. We conclude that feedback from at least some part of the chest wall is required to produce a volume- and frequency-dependent inhibition of inspiratory muscle activity observed during mechanical ventilation.

Respiratory function of velopharyngeal constrictor muscles during wakefulness in normal adults

1997 ◽  
Vol 82 (2) ◽  
pp. 584-591 ◽  
Author(s):  
Sandrine H. Launois ◽  
Judy Tsui ◽  
J. Woodrow Weiss
Keyword(s):  
Respiratory Function ◽  
Normal Subjects ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Tonic Activity ◽  
Intrasubject Variability ◽  
Phasic Activity ◽  
Oral Breathing ◽  
Levator Veli Palatini ◽  
Normal Adults

Launois, Sandrine H., Judy Tsui, and J. Woodrow Weiss.Respiratory function of velopharyngeal constrictor muscles during wakefulness in normal adults. J. Appl. Physiol. 82(2): 584–591, 1997.—The levator veli palatini (LVP) and the superior pharyngeal constrictor (SPC) influence velopharyngeal patency and soft palate position, but their behavior during respiration is incompletely characterized. To further clarify their respiratory function, we recorded electromyographic activity (EMG) in the LVP and the SPC in awake normal subjects breathing orally. EMG data were obtained in six subjects for the LVP and in nine subjects for the SPC. EMG activity and timing and ventilation were measured during isocapnic hypoxia and hyperoxic hypercapnia. Phasic EMG activity was inconsistently present during unstimulated oral breathing. Timing of EMG phasic activity was variable for both muscles. Peak LVP activity was mainly or exclusively expiratory in three of six subjects. Peak SPC activity was mainly or exclusively expiratory in five of nine subjects. With chemostimulation, recruitment of phasic activity was observed in the LVP in four of six subjects and in the SPC in five of nine subjects. Tonic activity increased in four of six subjects for the LVP and in three of nine subjects for the SPC. However, the response was alinear, and intersubject as well as breath-to-breath variability was substantial. In conclusion, LVP and SPC are characterized by the high inter- and intrasubject variability of EMG activity, timing of activation, and response to chemostimulation.

Nonchemical influence of inspiratory pressure support on inspiratory activity in humans

1998 ◽  
Vol 85 (6) ◽  
pp. 2169-2175 ◽  
Author(s):  
Brigitte Fauroux ◽  
Daniel Isabey ◽  
Gilbert Desmarais ◽  
Laurent Brochard ◽  
Alain Harf ◽  
...  
Keyword(s):  
Pressure Support ◽  
Respiratory Activity ◽  
Motor Output ◽  
Inspiratory Pressure ◽  
Electromyographic Activity ◽  
Inspiratory Time ◽  
Transdiaphragmatic Pressure ◽  
Pressure Time ◽  
Inspiratory Pressure Support ◽  
Inspiratory Activity

To determine whether nonchemical inhibition of respiratory activity occurs during inspiratory pressure support (IPS) ventilation (IPSV), respiratory motor output (in 9 subjects), obtained by calculating transdiaphragmatic pressure-time products, and central respiratory output (in 5 subjects), obtained by integrating the electromyographic activity of the diaphragm (EMGdi) during mechanical inspiratory time, EMGdi per minute, and electrical inspiratory time, as determined from onset to peak EMGdi, were compared during spontaneous ventilation (control) and IPSV with (IPS+CO2) and without (IPS) correction of hypocapnia. Both IPS and IPS+CO2 induced significant decreases in transdiaphragmatic pressure-time products (46 ± 31 and 53 ± 23%, respectively), EMGdi during mechanical inspiratory time (49 ± 12 and 57 ± 14%, respectively), EMGdi per minute (65 ± 22 and 69 ± 15%, respectively), and electrical inspiratory time (73 ± 8 and 65 ± 6%, respectively). Because correction of hypocapnia failed to eliminate the marked inhibition of both respiratory and central motor output seen with IPS, we conclude that nonchemical inhibition of respiratory activity occurs during IPSV.

Thyroarytenoid muscle activity during hypoxia, hypercapnia, and voluntary hyperventilation in humans

1990 ◽  
Vol 69 (1) ◽  
pp. 268-273 ◽  
Author(s):  
G. Insalaco ◽  
S. T. Kuna ◽  
F. Cibella ◽  
R. D. Villeponteaux
Keyword(s):  
Vocal Cord ◽  
Base Line ◽  
Electromyographic Activity ◽  
Tonic Activity ◽  
Quiet Breathing ◽  
Phasic Activity ◽  
Voluntary Hyperventilation ◽  
Relative Decrease ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid

Intramuscular electromyographic activity of the thyroarytenoid (TA) muscle, a vocal cord adductor, was recorded in nine normal adult humans during progressive isocapnic hypoxia and hyperoxic hypercapnia. Four of the nine subjects also performed voluntary isocapnic hyperventilation. During quiet breathing of room air, the TA exhibited phasic activity in expiration and often tonic activity throughout the respiratory cycle. Both phasic and tonic TA activity progressively decreased with either increasing hypoxia or hypercapnia. Tonic activity appeared to decrease more rapidly than phasic activity with increasing chemical stimulation. At comparable tidal volume increments, the relative decrease in phasic TA activity appeared to be greater under hypoxic than under hypercapnic conditions. During voluntary isocapnic hyperventilation, phasic TA activity decreased without significant change in tonic activity. At tidal volumes approximately double those of base line, the relative decrease in TA activity was similar during both hypercapnia and voluntary hyperventilation, although differences appeared at higher tidal volumes. The results, in combination with recent findings in humans regarding the posterior cricoarytenoid muscle, a vocal cord abductor, suggest that vocal cord position is dependent on the net balance of counteracting forces not only during quiet breathing but also during involuntary and voluntary hyperpnea.

Immediate diaphragmatic electromyogram responses to imperceptible mechanical loads in conscious humans

1992 ◽  
Vol 73 (1) ◽  
pp. 248-259 ◽  
Author(s):  
E. J. Kobylarz ◽  
J. A. Daubenspeck
Keyword(s):  
Electrical Activity ◽  
Lung Volume ◽  
Muscle Activity ◽  
Normal Subjects ◽  
Tonic Activity ◽  
Phasic Activity ◽  
Mechanical Loads ◽  
Oral Airway ◽  
Pattern Regulation ◽  
Adaptive Pattern

We used an esophageal electrode to measure the amplitude and neural inspiratory and expiratory (N TE) timing responses of crural diaphragmatic electrical activity in response to flow-resistive (R) and elastic (E) loads at or below the threshold for conscious detection, applied pseudorandomly to the oral airway of eight normal subjects. We observed a rapid first-breath neural reflex that modified respiratory timing such that N TE lengthened significantly in response to R loads in six of eight subjects and shortened in response to E loading in six of seven subjects. The prolongation of N TE with R loading resulted primarily from lengthening the portion of N TE during which phasic activity in the diaphragm is absent (TE NDIA), whereas E loading shortened N TE mainly by reducing TE NDIA. Most subjects responded to both types of loading by decreasing mean tonic diaphragmatic activity, the average level of muscle activity that exists when no phasic changes are occurring, as well as its variability. The observed timing responses are consistent in direction with optimally adaptive pattern regulation, whereas the modulation of tonic activity may be useful in neural regulation of end-expiratory lung volume.

scholarly journals Vagal feedback in the entrainment of respiration to mechanical ventilation in sleeping humans

2000 ◽  
Vol 89 (2) ◽  
pp. 760-769 ◽  
Author(s):  
Peggy M. Simon ◽  
Alfred M. Habel ◽  
J. Andrew Daubenspeck ◽  
J. C. Leiter
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Rate ◽  
Eye Movement ◽  
Lung Transplant ◽  
Respiratory Activity ◽  
Nrem Sleep ◽  
Normal Subjects ◽  
The Other ◽  
Absolute Requirement ◽  
Striking Contrast

We studied the capacity of four “normal” and six lung transplant subjects to entrain neural respiratory activity to mechanical ventilation. Two transplant subjects were studied during wakefulness and demonstrated entrainment indistinguishable from that of normal awake subjects. We studied four normal subjects and four lung transplant subjects during non-rapid eye movement (NREM) sleep. Normal subjects entrained to mechanical ventilation over a range of ventilator frequencies that were within ±3–5 breaths of the spontaneous respiratory rate of each subject. After lung transplantation, during which the vagi were cut, subjects did demonstrate entrainment during NREM sleep; however, entrainment only occurred at ventilator frequencies at or above each subject's spontaneous respiratory rate, and entrainment was less effective. We conclude that there is no absolute requirement for vagal feedback to induce entrainment in subjects, which is in striking contrast to anesthetized animals in which vagotomy uniformly abolishes entrainment. On the other hand, vagal feedback clearly enhances the fidelity of entrainment and extends the range of mechanical frequencies over which entrainment can occur.

Sensation of dyspnea during hypercapnia, exercise, and voluntary hyperventilation

1990 ◽  
Vol 68 (5) ◽  
pp. 2100-2106 ◽  
Author(s):  
T. Chonan ◽  
M. B. Mulholland ◽  
J. Leitner ◽  
M. D. Altose ◽  
N. S. Cherniack
Keyword(s):  
Visual Analog Scale ◽  
Line Intensity ◽  
Time Course ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Base Line ◽  
Analog Scale ◽  
Voluntary Hyperventilation ◽  
The Difference ◽  
End Tidal

To determine whether the intensity of dyspnea at a given level of respiratory motor output depends on the nature of the stimulus to ventilation, we compared the sensation of difficulty in breathing during progressive hypercapnia (HC) induced by rebreathing, during incremental exercise (E) on a cycle ergometer, and during isocapnic voluntary hyperventilation (IVH) in 16 normal subjects. The sensation of difficulty in breathing was rated at 30-s intervals by use of a visual analog scale. There were no differences in the level of ventilation or the base-line intensity of dyspnea before any of the interventions. The intensity of dyspnea grew linearly with increases in ventilation during HC [r = 0.98 +/- 0.02 (SD)], E (0.95 +/- 0.03), and IVH (0.95 +/- 0.06). The change in intensity of dyspnea produced by a given change in ventilation was significantly greater during HC [0.27 +/- 0.04 (SE)] than during E (0.12 +/- 0.02, P less than 0.01) and during HC (0.30 +/- 0.04) than during IVH (0.16 +/- 0.03, P less than 0.01). The difference in intensity of dyspnea between HC and E or HC and IVH increased as the difference in end-tidal PCO2 widened, even though the time course of the increase in ventilation was similar. No significant differences were measured in the intensity of dyspnea that occurred with changes in ventilation between E and IVH. These results indicate that under nearisocapnic conditions the sensation of dyspnea produced by a given level of ventilation seems not to depend on the method used to produce that level of ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Electromyographic activity from human laryngeal, pharyngeal, and submental muscles during swallowing

1999 ◽  
Vol 86 (5) ◽  
pp. 1663-1669 ◽  
Author(s):  
A. L. Perlman ◽  
P. M. Palmer ◽  
T. M. McCulloch ◽  
D. J. Vandaele
Keyword(s):  
Muscle Activity ◽  
Total Duration ◽  
Normal Subjects ◽  
Electromyographic Activity ◽  
Surface Electrodes ◽  
Submental Muscles ◽  
Temporal Relationships ◽  
Dependent Change ◽  
Significant Difference ◽  
High Level

The durations and temporal relationships of electromyographic activity from the submental complex, superior pharyngeal constrictor, cricopharyngeus, thyroarytenoid, and interarytenoid muscles were examined during swallowing of saliva and of 5- and 10-ml water boluses. Bipolar, hooked-wire electrodes were inserted into all muscles except for the submental complex, which was studied with bipolar surface electrodes. Eight healthy, normal, subjects produced five swallows of each of three bolus volumes for a total of 120 swallows. The total duration of electromyographic activity during the pharyngeal stage of the swallow did not alter with bolus condition; however, specific muscles did show a volume-dependent change in electromyograph duration and time of firing. Submental muscle activity was longest for saliva swallows. The interarytenoid muscle showed a significant difference in duration between the saliva and 10-ml water bolus. Finally, the interval between the onset of laryngeal muscle activity (thyroarytenoid, interarytenoid) and of pharyngeal muscle firing patterns (superior pharyngeal constrictor onset, cricopharyngeus offset) decreased as bolus volume increased. The pattern of muscle activity associated with the swallow showed a high level of intrasubject agreement; the presence of somewhat different patterns among subjects indicated a degree of population variance.

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