Which part of the brain is responsible for thermoregulation?

Answer & Solution:

The correct answer is (b) hypothalamus 

The anterior portion of the hypothalamus, especially the preoptic area, is concerned with regulation of body temperature. An increase in temperature of the blood flowing through this area increases activity of temperature-sensitive neurons, whereas a decrease in temperature decreases their activity. In turn, these neurons control mechanisms for increasing or decreasing body temperature. The anterior hypothalamic-preoptic area contains large numbers of heat-sensitive neurons, as well as about onethird as many cold-sensitive neurons. These neurons are believed to function as temperature sensors for controlling body temperature. The heat-sensitive neurons increase their firing rate 2- to 10-fold in response to a 10°-C increase in body temperature. The cold-sensitive neurons, by contrast, increase their firing rate when body temperature falls. The temperature sensory signals from the anterior hypothalamic-preoptic area are also transmitted into this posterior hypothalamic area. Here the signals from the preoptic area and the signals from elsewhere in the body are combined and integrated to control the heat-producing and heat-conserving reactions of the body.