Final answer:
Vasodilation is the widening of blood vessels in the skin to regulate body temperature. It is triggered by an increase in body temperature and signals from the hypothalamus. This process helps in losing body heat and is important for temperature regulation.
Step-by-step explanation:
Vasodilation is the process by which blood vessels in the skin widen, allowing more blood to flow closer to the surface of the body. This helps in losing body heat and regulating body temperature. The triggers for skin vasodilation include an increase in body temperature and signals from the brain's hypothalamus. For example, when body temperature rises, the hypothalamus sends nerve signals to sweat glands to release sweat and also causes dilation of blood vessels in the skin.