nociceptor

(redirected from Pain fibers)
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nociceptor

[′nō·sə‚sep·tər]
(physiology)
A sensory nerve ending that is particularly sensitive to noxious stimuli such as chemical changes in surrounding tissue evoked by injury.
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References in periodicals archive ?
Turning off the pain fibers could curb coughing, the researchers surmised.
This anatomic "border" is of special clinical interest because external pain fibers end at this point, and most people have no sensation above this line.
There are several reasons for this increased sensitivity: (a) the number of nociceptive nerve fibers in the skin of the neonate is similar to and possibly even greater than the number found in the adult; (b) incomplete myelination of pain fibers in the preterm infant does not hinder pain transmission, and the shorter distances of the immature pain pathways offset any slowing of velocity that may be caused by lack of myelination; (c) pain neurotransmitters are found in abundance and are functional in the fetus; and (d) there are large receptive fields of neurons in the somatosensory cortex (Anand, 1998; Anand, Phil, & Carr, 1989; Perreault, et al.
They are thought to occur when pain fibers in the head release chemicals that cause blood vessels to expand.
It was clear that in some (if not most) patients, pain fibers passing from the geniculate ganglion to the brain did so through the motor trunk of the VIIth nerve, as well as the nervus intermedius.
As discussed previously, once the pain receptors have received a stimulus, they send a pain signal along the afferent (sensory) nerve pathway of pain fibers back to the spinal cord.
Patting at a rate of twice a second seems to inhibit the small pain fibers of the nervous system, providing some relief.
Besides cordotomy, surgery within the brain or spinal cord to relieve pain includes severing connections at major junctions in pain pathways, such as at the places where pain fibers cross from one side of the cord to the other, or destroying parts of important relay stations in the brain like the thalamus, an egg-shaped cluster of nerve cells near the center of the brain.
The pain message starts with the stimulation of special pain fibers in the nerve endings embedded in the skin.
The clinical relevance of the effect on pain fibers in nonclinical studies has not been established.
Because the histamine-sensing itch fibers could not detect itchy mechanical stimuli, like a scratchywool sweater, the researchers turned to another likely culprit: pain fibers.