How do our nerves "feel" pain?

There are nociceptors at the end of the nerve are stimulated by temperature, pressure, or chemicals and when they get stimulated, they release neurotransmitters that travel to the next nerve cell and then stimulate that cell, and this happens over and over until it gets to the brain and in the brain, this is interpreted as pain. Interestingly, with the expression "it is just in your head." It is!