Histology of the Carotid Body

Abstract

DE CASTRO'S histological¹ and Heyman's physiological² investigations on the carotid body have provided new and important evidence of a peripheral control of respiration and circulation. Histologically, much work has been done to elucidate the mode of nervous innervation of the chemo-receptive tissue in the carotid body; but little is known of the underlying mechanism by which chemical changes in the blood give rise to afferent impulses in the sinus nerve, for example, whether the receptors concerned are specialized in relation to the nature and concentration of particular stimuli. Anderson and Zotterman³ were able to demonstrate that specialized receptors for ‘water taste’ as distinct from acid receptors exist in the frog's tongue. Von Euler, Liljestrand and Zotterman⁴ obtained results “which strongly suggest identical receptors” for anoxic and hypercapnic stimulation. Winder⁵ leaves open the question of separate receptor sets for oxygen and carbon-dioxide stimulation.