HYPOTHERMIA WHAT'S THE HYPE?

摘要

Animals attempt to tightly regulate their core body temperature to within a very narrow, species-specific range called a set-point. Thermoregulation occurs when the body's thermal receptors detect temperature changes in the peripheral zone (e.g., skin, extremities, and subcutaneous tissues) and core zone regions (e.g., brain, heart, and great vessels). These thermal variations are then transmitted from the thermal receptors to the posterior hypothalamus via the spinal cord. Since heat travels from high to low temperatures, thermal homeostasis (or maintaining the set-point) is achieved by modulating the distribution and flow of blood to organs, viscera, and skin by way of either vasoconstriction or vasodilation. Initial heat loss induces cutaneous vasoconstriction in an attempt to limit heat loss and maintain core temperature. When vasoconstrictive efforts fail to resolve hypothermia, heat production is augmented via increasing muscle tone and shivering. Furthermore, non-shivering thermogenesis occurs with epinephrine secretions.