Effect of respiratory muscle tension on lung volume.
J Appl Physiol (1985)
; 73(6): 2283-8, 1992 Dec.
Article
en En
| MEDLINE
| ID: mdl-1490934
ABSTRACT
The chest wall is modeled as a linear system for which the displacements of points on the chest wall are proportional to the forces that act on the chest wall, namely, airway opening pressure and active tension in the respiratory muscles. A standard theorem of mechanics, the Maxwell reciprocity theorem, is invoked to show that the effect of active muscle tension on lung volume, or airway pressure if the airway is closed, is proportional to the change of muscle length in the relaxation maneuver. This relation was tested experimentally. The shortening of the cranial-caudal distance between a rib pair and the sternum was measured during a relaxation maneuver. These data were used to predict the respiratory effect of forces applied to the ribs and sternum. To test this prediction, a cranial force was applied to the rib pair and a caudal force was applied to the sternum, simulating the forces applied by active tension in the parasternal intercostal muscles. The change in airway pressure, with lung volume held constant, was measured. The measured change in airway pressure agreed well with the prediction. In some dogs, nonlinear deviations from the linear prediction occurred at higher loads. The model and the theorem offer the promise that existing data on the configuration of the chest wall during the relaxation maneuver can be used to compute the mechanical advantage of the respiratory muscles.
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Banco de datos:
MEDLINE
Asunto principal:
Músculos Respiratorios
/
Pulmón
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
1992
Tipo del documento:
Article