THE NERVOUS CONTROL OF RESPIRATION IN KITTENS

Abstract

Ontogenetic development of the vagus-phrenic portion of the respiratory mechanism has been completed at birth and is functionally active from that time onward. A closer relationship between the vagus and phrenic nerves in respiratory regulation than between the vagus and dorsal spinal nerve roots is demonstrated. Development of the mechanism for adequate thoracic respiration is not completed before the end of the 3rd wk. after birth in the kitten, as is shown by its lack of ability to compensate for failure of diaphragmatic respiration. The functional relationship of the nuclei in the corpora quadrigemina to the costal respiratory mechanism is not established earlier than 10 days after birth and possibly later.