Cutaneous vasomotor nerves to the head and trunk

Abstract

Simultaneous measurements of skin temperature of various skin areas of the body were made during indirect cooling and heating of the body. Cooling the body caused a much larger fall in the nose and finger temperature than in mouth temperature, indicating active vasoconstriction in these areas. In the ear, cheek, chest and forehead there was no evidence for vasoconstriction. Evidence of vasodilatation in all the skin areas studied was obtained when the body was indirectly heated. Blocking the vasomotor nerves to the ear resulted in a large increase in skin temperature and, during body heating, the skin temperature of the normal ear did not exceed that of the nerve-blocked ear. It was concluded that the changes in ear blood flow subserving temperature regulation are mainly due to alterations in vasoconstrictor tone. In the chest and cheek, cutaneous nerve block did not alter skin temperature, yet it reduced the rise in skin temperature normally seen during body heating. It was concluded that the vasodilatation normally seen in these areas is not due to release of vasoconstrictor tone, but rather to an active vasodilator mechanism, mediated through fibers running with the cutaneous nerves. Submitted on May 27, 1960