smärtsignalen
Smärtsignalen, which translates to “pain signal” in English, refers to the complex neurophysiological process by which the nervous system detects and conveys information about tissue damage or potentially harmful stimuli. The pathway begins at specialized nociceptors located in skin, muscles, joints and internal organs. These free‑ending nerve endings respond to mechanical, thermal, or chemical changes that exceed certain thresholds. When activated, nociceptors open ion channels that trigger depolarisation and the generation of action potentials. These electrical impulses travel along peripheral afferent fibers—primarily Aδ and C fibres—toward the dorsal horn of the spinal cord.
Within the dorsal horn, pain signals are synaptically transmitted to second‑order neurons. Here, neurotransmitters such as
The smärtsignal’s sensitivity and gain can be modulated by descending pathways originating in the brainstem. These
Clinically, understanding the mechanics of the smärtsignal underpins diagnostics and treatments for pain, such as pharmacologic