Final answer:
Thermal receptors respond to variations in temperature and can be stimulated by both low and high temperatures. They are primarily found in the skin and play a crucial role in the body's temperature regulation by triggering appropriate responses to maintain internal stability.
Step-by-step explanation:
Thermal receptors are specialized nerve cells that respond to changes in temperature. They can be stimulated by both low and high temperatures, depending on the type of receptor. There are cold receptors that respond to lower temperatures, while hot receptors are triggered by higher temperatures. Both types of thermoreceptors are found primarily in the skin and are essential for the sensation of temperature and for the body to maintain its internal thermostat.
For instance, when body temperature rises, these receptors in the skin and brain sense the change. If an individual is too hot, this triggers a response from the brain, causing the skin to produce sweat and the blood vessels near the skin surface to dilate. This in turn helps to lower body temperature. When exposed to extreme temperatures, whether hot or cold, this might elicit a pain response, as the pathways for temperature and pain overlap, and nociceptors get activated by extreme thermal stimuli.