REACTIONS OF LARGE AND SMALL ARTERIES IN MAN TO VASOCONSTRICTOR STIMULI

Abstract

The possibility of synergistic participation of the large arteries in the reactions of the small arteries and arterioles supplied by them, was studied in man, on the radial artery-digital artery field, using the photoelectric plethysmographs, previously described, to record the reactions. The responses observed involved spontaneous waves, the reactions to a deep breath, the breath held, the cold pressor test, loud noises and various psychic stimuli. Radial artery participation in the vasoconstriction of the finger arteries was irregular and most obvious in instances of massive disturbances of the circulation. The degree of constriction of the finger arteries had little predictive value with respect to the occurrence of constriction in the radial artery. The data show selection with respect to the participation, and with respect to the intensity of the participation, of the radial artery in the vasomotor responses of the small arteries and arterioles which it supplies.