Mode of action of reflexes due to intravascular administration of certain substances on respiration and blood circulation

Summary

In experiments staged on cats, the author made use of the method of perfusion of the hind limb. In intravascular injection of chemical irritants, the vascular receptors play no essential role in the mechanism of respiratory and circulatory reflex reactions. A difference of reactions of respiration and circulation, observed in intra arterial and intravenous injection of certain chemical irritants, is called forth by irritation of receptors of various organs which are the source of counter-reflex influences on the respiration and circulation. Upon intra-arterialinjection, excitation takes place in the receptors of the organ into the artery of which the chemical irritant was introduced, attended by stimulation of the respiratory and vasomotor centers. Intravenous injection of chemical irritants excites the receptors of organs of the lesser circulation, bringing about reflex inhibition of these centers.