The blood flow changes observed in our experiments look small in terms of forearm blood flow. The graphic is a schematic representation of the change shown in the summary data -- only in the order of a milliliter per minute per 100 ml of forearm.

Keep in mind, though, that skin makes up only, say, 5% of total limb volume. According to that proportion, the changes amount to something like 20ml/min per 100 ml of skin, a substantial change. In terms of cardiac output, this might amount to a change of 400 ml/min. This estimate can be arrived at, for a good-sized person, 2 square meters total body surface area, by estimating total skin volume of 2 liters, or by an estimate based upon the surface area of a 100ml forearm segment. Both estimates assume that the skin blood flow response is uniform over the entire body; unlikely, perhaps.

The estimated total skin blood flow change is consistent with estimates of the flow levels necessary for the transfer of body heat to the skin surface.

This is the last page in the linear sequence.

rationale in experimental design(with links to methods pages)
Summary data from experiments
return to index page