Describe how the body maintains homeostasis when there is a drop in body temperature.

The body does this through the process of negative feedback. Thermoreceptors detect the decrease in temperature, and send a signal (via sensory neurones) to the temperature-regulating centre in hypothalamus. This centre coordinates a response and sends it to the effectors (via motor neurones), which carry out a response. Examples of effectors are arrector pili muscles, which contract and cause hair to stand on end, thus trapping a layer of air. Another response is vasoconstriction, which reduces heat loss through the skin. Sweat secretion from glands also decreases or stops during low body temperatures. These responses stop when the body has reached optimal temperature.