Neurons that transmit information from external and internal stimuli to the CNS (light, sound, temperature, etc).
Sensory Neurons
Crucial ascending pathway in the CNS that transmits sensory information (pain, temperature, and crude touch) from the body to the brain.
Anterolateral System
A. Drugs that bind to and activate receptors on nerve cells, primarily to receive pain
B. Receptors on cells in the brain, spinal cord, and other organs. Part of the natural system for regulating pain, breathing, and stress responses.
Opioids/Opioid Receptors
Thin, myelinated nerve fibers that transmit sharp, acute, and localized pain signals quickly.
Ex: initial pain when touching something hot
A-Delta Fibers
Chronic pain that comes from dysfunction/damage to the nervous system.
Ex: burning, tingling, numbness, sensitivity
Neuropathic Pain
The sensory neurons devoted to detecting pain and extreme temperatures are not properly developed; causes an inability to experience either.
Hereditary Sensory and Autonomic Neuropathy (HSAN)
Spinal cord –> thalamus. Critical in perceiving the location, intensity, and quality of pain.
Spinothalamic Tract
Small device that attaches to the skin and produces mild electrical currents. (I use it for cramps!)
Transcutaneous Electrical Nerve Stimulation (TENS)
Naturally occurring opioid peptides; act as the body’s natural painkillers.
Endorphins
Type of sensory nerve fibers that play a crucial role in pain perception and other perceptions.
C-Fibers
Phenomenon where pain is perceived in an area different from its actual source.
Referred Pain
Sensory receptors specialized in responding to harmful stimuli (intense pressure, tissue damage, or extreme temperatures).
Nociceptors
Point-for-point correspondence between a specific area of the body and a specific point on the CNS
Somatotopic
The brain’s ability to convince us that we feel better after taking something that does not have a direct effect on the body.
Placebo Effect
When released due to inflammation or injury, promotes pain (PNS). Can have pain relieving effects (CNS).
HIstamine
Type of nociceptive pain originating from internal organs of the chest, abdomen, and pelvis. Diffused, poorly localized (ache pressure, cramping).
Visceral Pain
Primary relay center for all sensory information. Pain signals are actively processed, integrated, and modulated.
Spinal Cord
Highest level of pain processing in the brain, integrating sensory information with cognitive and emotional factors, forming the subjective experience of pain.
Cerebral Cortex
Posterior: Processing the physical intensity and location of pain
Anterior: Integrates sensory data with emotional and motivational information to generate the feeling of unpleasantness
Insula/Insular Cortex
Critical for pain modulation, primarily through the release of serotonin.
Raphe Nucleus
Responsible for processing the sensory-discriminative aspects of pain
Somatosensory Cortex
Surrounds the cerebral aqueduct; primarily the body’s descending pain-modulating system. Can inhibit OR facilitate pain.
Periaqueductal Gray (PAG)
Modulates pain sensation; another crucial relay in the descending pain-modulating pathway.
Medulla
Actively processes and modulates pain signals BEFORE they are sent to the cerebral cortex. Encompasses sensory discrimination AND the emotional experience of pain.
Thalamus
