Effect of Change in Posture on the Blood Flow Through the Fingers and Toes

¹ From the Department of Physiology, The Queen's University, Belfast, Northern Ireland

Heat eliminations from the toes and middle finger of the human subject were measured calorimetrically when the subject was lying horizontal with extremities at heart level and when standing erect with the extremities fully dependent. It was found that the finger heat elimination was not significantly altered, but that that from the toes rose slightly on standing. Other experiments were carried out where a) the leg of a horizontal subject was lowered from heart level to a dependent position while the heat elimination from the toes was measured (the heat elimination was found to increase with dependency); and b) the heat eliminations from the finger were measured at the heart level of a subject when horizontal and at heart level and fully dependent when standing erect (no significant change was observed). It is concluded that centrally-induced reflexes oppose the local effects of increased transmural pressure and result in blood flow through the fingers and toes remaining virtually unaltered with change in posture.