REACTIVITY OF INTACT BLOOD VESSELS OF THE FINGERS AND TOES TO SENSORY STIMULI IN NORMAL RESTING ADULTS, IN PATIENTS WITH HYPERTENSION, AND IN SENILE SUBJECTS 1

Abstract

The time of reaction (constriction) of small blood vessels of the fingers and toes was studied by the use of a plethysmographic technique. The mean reaction time in the fingers of normal persons was 3.12 secs., of hypertensive patients 2.94 secs., and of senile subjects 3.86 secs. The values for the toes in the same 3 groups respectively were 3.42, 3.24 and 4.25 secs. All of these values were considered statistically significant. The stimuli (diffuse light, heat, cold, pin prick, sudden loud noise, and electric shock) gave no significant differences. Although not all of the individual stimuli resulted in vasoconstriction, when this did occur, the time of reaction was always close to the mean values. The difference between the reaction times for fingers and toes was ascribed to the increased length of sympathetic nervous pathway over which impulses had to travel to reach the toes.