Figure 1.
Regulation of physiological thermoeffector responses to cold exposure. Decreases in mean skin temperature and core temperature are sensed by peripheral (skin) and central thermoreceptors. Cutaneous and central afferent signals are integrated in the preoptic area of the hypothalamus, which elicits insulative (heat-conserving) and metabolic (heat-generating) thermoeffector responses. Sympathetic signals descending from the pre-optic area mediate cutaneous vasoconstriction and non-shivering thermogenesis, while descending somatomotor signals activate shivering thermogenesis. POA, preoptic area; Tc, core temperature; Tsk, skin temperature.