A<unk>  is a sensory receptor that sends signals that cause the perception of pain in response to potentially damaging stimulus.<unk> s are the nerve endings responsible for nociception, one of the two types of persistent pain (the other, neuropathic pain, occurs when nerves in the central or peripheral nervous system are not functioning properly). When they are activated,<unk> s can trigger a reflex.
Nociceptor
Sensory receptor
Afferent nerve
Efferent nerve
Postganglionic fibers
Interneuron
Nerve
Spindle neuron