Action potentials of accessory respiratory muscles in dogs

¹ Department of Gastrointestinal Research, Medical Research Institute, Michael Reese Hospital, Chicago, Illinois

Among 30 so-called accessory respiratory and other muscles tested, the presence of rhythmic respiratory impulses was found in 12. Both expiratory and inspiratory impulses were detected in certain muscles, in others only in- or expiratory ones. The muscles with most frequent inspiratory impulses were the intercartilaginous intercostal muscles, the intrinsic muscle of the larynx and the nostril; those with expiratory impulses were abdominis, external and internal oblique, transversus abdominis, scalenus anterior, and lower interosseous intercostal muscles.