Noeud Vital and the Respiratory Centers.

We now recognize that the main breathing generator resides principally in the medulla oblongata. Vivisectionists-specifically, Julien Legallois-discovered "the respiratory center." Cutting through the brainstem stops respiration but not if the medulla remains intact and the brain is sliced in successive portions. Pierre Flourens localized surgical ablation experiments further identified a 1-mm area in the medulla, which he called vital knot or node (noeud vital). Detailed characterization had to wait until the 1920s, when Lumsden carried out more specific transection experiments to improve morphological differentiation of the respiratory center into inspiratory and expiratory divisions.