C_S_D 4430 Lecture Notes - Lecture 37: Nociceptor, Golgi Tendon Organ, Proprioception
Document Summary
There are separate receptors for hot and cold. Using small cold and warm probes, researchers have mapped the skin and found that there are spots about 1mm wide that are especially sensitive to either hot or cold, but not both. The locations for hot an cold sensitivity are different, showing that spate receptors encode them. There are also small areas of skin in between the hot and cold spots that are relatively insensitive to temperature. Thermoreceptors adapt quickly and therefore response best to temperature changes. We experience their actions as pain or discomfort. They are present in most body tissues, but are noticeably absent from the brain itself. Mechanical nociceptors respond to strong pressure particularly from sharp objects. Chemically-sensitive nociceptors respond to a variety of chemicals from the environment as well as the tissue itself. Thermal nociceptors signal either burning heat or extreme cold. Polymodal nociceptors respond to combinations of mechanical, thermal, and chemical stimuli.