[The descending pathways of the medial nuclei of the respiratory center to the respiratory muscles].

Electrical activity of the phrenic, external and internal intercostal nerves was studied in anesthetized cats during electrical stimulation of the inspiratory "points" of the reticular gigantocellular nucleus (medial zone of the respiratory center). Structural characteristics of reflex responses of phrenic and intercostal nerves to stimulation of various respiratory and nonrespiratory bulbar sites as well as their respiratory modulation, were analyzed. The organisation of probably neurophysiological mechanism of phrenic and intercostal responses to stimulation of the medial nucleus of the respiratory center, is discussed.