Respiratory muscles in emphysema: effects of chest distension

Besides increasing the work of ventilation, emphysema increases lung volume which in itself has a deleterious effect on the inspiratory muscles. We re view here the effects of an acute change in lung volume on the configuratio n of the rib cage and muscle function. We also discuss the effects of the c hronic distension associated with emphysema. The effects produced by change s in muscle length and configuration on the mechanical force and action of inspiratory muscles is derailed with particular focus on the diaphragm and its structural adaptations to experimental emphysema. We also analyze the a ctivation pattern of inspiratory and expiratory muscles during the breathin g process in patients with emphysema. Finally we discuss the effects of sin gle-long transplantation and reduction surgery on chest distension and impr oved inspiratory muscle function.