Pathological algic system
Emerged in the afferent input (dorsal horns of the
spinal cord or caudal trigeminal nucleus) generator itself is not able to cause
pathological pain. Local generator regional changes may lead to spinal cord: a
relief flexor reflex, changes in motor neuron activity, and others.
Pathological pain as suffering and as a syndrome
occurs when the process involved and other departments of pain sensitivity
system, in particular brain structures responsible for manifestation of the
feelings of pain and its emotional coloring.
Participation in these structures forming
pathological pain is not just in their responses to nociceptive signals
received, both in physiological pain. Department of pain sensitivity system, in
which there was a generator, becomes hyperactive and acquires the ability to
change the functional state of the neurons of other levels. From primary and
secondary educational change processes plastic is formed and fixed pain
sensitivity system integration of new pathologic - abnormal algic system (PAS).
That pain sensitivity system department, which is formed under the influence
pathologic algic system plays the role of determinants of PAS.
If abnormal algic system is unformed, if it does
not include the higher parts of the pain sensitivity of the system - the
thalamus and the cerebral cortex - pain does not appear behaviorally. This
situation can occur if the nociceptive neurons in the dorsal horn and are not
active enough or do not form a generator if the higher parts of pain
sensitivity have an effective braking system control. In both cases, the role
of the supervisory mechanism that prevents the formation and activity of
pathological algic system plays antinociceptive system.
The following table shows the levels of education
and pain sensitivity of the system, included in the pathological algic system,
which is due to the enhanced nociceptive stimulation from the periphery. These
structures constitute the main trunk of PAS, on them are due to the different
departments of the central nervous system, involvement in the pathological
process which causes additional syndromes. The latter include autonomic
disturbances, changes in the cardiovascular system and microcirculation,
disregulation functions of internal organs, endocrine and immune systems,
psycho-emotional disorders, and others.
Current pain and nature of attacks of pain depends
on the characteristics of activation and activity of PAS. An important role in
this process is played particularly activation of the generator, which is
connected with the activity of PAS. With a significant violation of the brake
and increased excitability of neurons is their gipersinhronizatsiya and
discharge pulse generator bystronarastajushchih flow. If this flow is as fast
and enhanced activation algic pathological system, it has a twinge of
paroxysmal character. If the generator develops its activity slowly and slowly
activated PAS, the intensity of pain during an attack is slowly growing; when
the tonic activity of the generator and PAS constant pain.
Table. Levels of education and altered pain sensitivity system constituting
the main trunk system pathological algic
Peripheral units
|
Sensitize nociceptors, ectopic excitation foci
(and regenerating damaged nerves, demyelinated areas nerve neuroma);
giperaktivirovannyh group of neurons of the spinal ganglia
|
spinal level
|
Units of hyperactive neurons (generators) in afferent
nociceptive relay - in the dorsal horns of the spinal cord and in the nucleus
of the spinal tract of the trigeminal nerve (caudal nucleus)
|
supraspinal level
|
The nuclei of the reticular formation of the
barrel, nucleus of the thalamus, and the sensorimotor orbitofrontal cortex,
emotiogenic structure
|
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