Last updated: Thu, Nov 21, 2024
The pain system is complex. Pain signals normally originate in sensory nerves (nociceptors), which are complex. The sensory neurons feed into the spine, which is active and complex. Signals that originated in nociceptors then arrive in the brain, which assesses, responds, and appraises. This section deals with nociceptors and the spine.
The pain system is dynamic. It constantly adjusts its sensitivity for at least two purposes. First, it must try to keep itself steady and stable. This steadiness and stability is called homeostasis. Second, it must adapt itself to meet stresses. This is called allostasis. Among the stresses the pain system must adapt to are unusual intensity or duration of pain, the necessity to respond to injuries of all kinds, and the need to support behaviors such as flight-or-fight, whenever the need arises.
This section describes the pain system from nociceptors, through the spine, and up to the brain. The physical form of the nerves, called morphology, is a basic aspect. The functioning of the neural system in the sensory nerves and the spine is active, not passive. The active nature of these tissues supports homeostasis and allostasis. It also accounts for some important behaviors of the pain system, including behaviors that may lead to troublesome pain.
Within this section...
From Nociceptors to the Brain (This page is incomplete.)
Injury, Inflammation, and Healing (This page is incomplete.)
The Spine's Organization (Last updated: Thu, Nov 21, 2024)
Pain Phenomena of the Spine and Periphery (Last updated: Wed, Jul 5, 2017)
Regulation of Spinal Sensitivity (Last updated: Thu, Jun 22, 2017)
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Pain Science 3: Neuroscience and the Brain (Last updated: Fri, Mar 7, 2025)