Respiratory function of velopharyngeal constrictor muscles during wakefulness in normal adults.
J Appl Physiol (1985)
; 82(2): 584-91, 1997 Feb.
Article
en En
| MEDLINE
| ID: mdl-9049741
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 and 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 higher inter- and intrasubject variability of EMG activity, timing of activation, and response to chemostimulation.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Músculos Faríngeos
/
Respiración
/
Vigilia
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
1997
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos