Effect of Local Cooling on Finger Blood Flow in Itidividzcdls Exposed to Wumz Ambient Temperatare’

T HE PREPONDERANCE OF PREVIOUS WORK indicates that blood flow to hands and feet depends on the thermoregulatory needs of the body, primarily, and to a much lesser extent on local thermal influences. In this report an attempt has been made to compare the relative influence of direct and indirect thermal stimuli in the control of blood flow through the terminal phalanx of the finger in individuals exposed to a warm ambient temperature. MATERIALS AND METHODS All the experiments were performed in a constant temperature room. A Burch-Winsor plethysmograph (I) was utilized for the finger vascular studies. Five cc. portions of the terminal phalanges (Ist, and or 3rd fingers) were inclosed in the plastic cups and fked at heart level. In. experiments in which local cooling of the finger were carried out, the plethysmograph cups were filled, except for a standard air space, with saline solution. The cup was surrounded by a plastic shell through which a thermoregulated air stream was circulated. The use of saline in the plethysmograph cup permitted lowerin