Control of respiratory frequency

Abstract
Previous work has shown that for a given level of alveolar ventilation there is a particular respiratory frequency which is least costly in terms of respiratory work. There is also a particular frequency, usually a different one, which is least costly in terms of average force of the respiratory muscles. Evidence is presented that in the resting guinea pig and in man at rest and during exercise natural breathing takes place at frequencies approximating the second optimum. From additional observations on the effects of changing the mechanical characteristics of the respiratory system on respiratory frequency it is concluded that the principal site of the sensory end of the control mechanism is in the lungs. Submitted on November 19, 1959