TIME REQUIRED FOR BLOOD TO FLOW FROM THE ARM AND FROM THE FOOT OF MAN TO THE CAROTID SINUSES

Abstract

No attempt has been made to review the literature on circulation time completely for this presentation. Extensive references may be found elsewhere.¹ All methods depend on determination of the time elapsing between intravascular injection of a substance and its arrival at another part of the body. This arrival may be determined objectively² or subjectively.³ Loevenhart and his associates⁴ noted marked respiratory stimulation in animals and man following intravenous injection of a solution of sodium cyanide and proposed the use of sodium cyanide for the determination of circulation time in man. Robb and Weiss, however, carried out the first clinical study. Since then there have been several reports.⁵ The principal site of action of the cyanide radical has been demonstrated by Heymans and his associates⁶ to be the carotid bodies. Winder and his associates⁷ confirmed this effect on the carotid reflex mechanism by direct