arising from a revenue to the central nervous system pathology
impulses from the periphery (as opposed to pain, which is determined by
survey, for example, palpation). Type of pain, its nature does not always depend on the intensity of initial
incentives. Abdominal organs usually
insensitive to many pathological stimuli, which when exposed to
skin causing intense pain. Ripping, cutting or casshing of internal organs
not accompanied by noticeable sensation. At the same time, tension and stress
wall of the hollow body irritate pain receptors. Thus, the tension of peritoneum
(tumor), stretching of the hollow body (eg biliary colic) or excessive muscle contraction
cause abdominal pain. Nociceptors hollow organs
abdomen (esophagus, stomach, intestines, gallbladder, bile and pancreatic ducts
) are localized in the muscular layer of their walls. Similar
receptors are present in the capsule of parenchymal organs such as liver, kidney,
spleen, and their strength is also accompanied by pain. Mesentery and parietal peritoneum
sensitive to painful stimuli, while the visceral peritoneum and greater omentum
lack of pain sensitivity.

Abdominal pain subdivided into acute, which develop as
usually quickly or, rarely, slowly and have short duration
(minutes, rarely a few hours), and chronic, characterized by a gradual increase in
. These pains persist or recur over
weeks and months. The etiological classification of abdominal pain is presented in Table
. 1.

The mechanism of pain in the abdomen divided into
visceral, parietal (somatic), reflected (irradiating) and
psychogenic.

Abdominal pain occurs in the presence of pathological stimuli in the internal organs and
conducted by sympathetic fibers. The main impulses for its occurrence are
sudden increase in pressure in the hollow body and stretching
its walls (the most common cause), stretching the capsule
parenchymal organs, the tension of the mesentery, vascular disorders.

Somatic pain is caused by the presence of pathological processes in
parietal peritoneum and tissues, with the end of the sensitive spinal nerves
.

main impulses for its occurrence are
damage to the abdominal wall and peritoneum.

Differential diagnostic signs of visceral and somatic pain
presented in Table. 2.

referred pain is localized in various areas, remote from
pathological focus. It arises in cases where the pulse of visceral pain
too intense (for example, the passage of a stone) or anatomical
organ damage (eg, impairment of bowel). Referred pain is transmitted to
surface areas of the body that have a common innervation with the spine affected
abdominal area. For example, with increasing pressure in the intestine
first arises visceral pain, which then radiates to the back, with biliary colic
- back in the right shoulder blade or shoulder.

Psychogenic pain occurs in the absence of peripheral effects or
when the latter acts as a trigger or predisposing factor. Special
role in creating it belongs to the depression. The latter often takes place hidden
and not recognized by patients. The close relationship of depression with chronic abdominal pain due to
common biochemical processes and, above all,
, lack of monoaminergic (serotonergic) mechanisms.
This confirms the high effectiveness of antidepressants, particularly inhibitors
serotonin reuptake in the treatment of pain. Nature of psychogenic pain
determined personality characteristics, influence of emotional, cognitive,
social factors, psychological stability of the patient and his past
«painful experience." The main features of these headaches are their duration,
monotony, diffuse and mix with other localizations (head
pain, back pain throughout the body). Psychogenic pain often can be combined with other
mentioned above types of pain and stay after their relief,
essentially transforming their character that should be considered when therapy.

One variety of the central pain genesis is
abdominal migraine. The latter ismorecommon in younger age, is intense
diffuse nature, but may be local in periomphalic area.
Characteristic accompanying nausea, vomiting, diarrhea, and autonomic dysfunction
(blanching and cold extremities, cardiac arrhythmias, blood pressure
, etc.), as well as migraine tsefalgiya and characteristic for it
provoking and accompanying factors. During the paroxysm
marked increase in the rate of linear flow in the abdominal aorta. The most important
control mechanisms of pain are the endogenous opioid system.
Opiate receptors localized in the sensory nerve endings in the spinal cord neurons
in stem nuclei in the thalamus and the limbic brain stasctures
brain. Relationship of these receptors with a number of neuropeptides such as endorphins and enkephalins
, determines the effect of morphine. Opiate system works on
follows: activation of sensory endings leads to the separation
substance P, which causes peripheral ascending and descending central
nociceptive (pain) impulses. Last activate the production of endorphins and enkephalins
that block release of substance P and reduce
pain.

essential in the formation of pain are serotonin and norepinephrine
. In the stasctures of the brain contains a large amount
serotonergic and noradrenergic receptors, and in the descending
antinociceptive (analgesic) stasctures include serotonergic and noradrenergic fibers
. The decrease in serotonin levels leads to a reduction
pain threshold and increased pain. Norepinephrine mediates the increase in activity
antinociceptive systems.

presence of abdominal pain syndrome requires in-depth survey
patient to clarify the mechanisms of its development and choice of treatment.
vast majority of patients with somatic pain, as a asle,
need surgical treatment. Visceral pain arising in patients with both
presence of organic lesions of the digestive system, and without them, are
consequence of a breach in the first place, the motor function of the latter. As a result
in hollow organs is increased pressure and / or there is stretching its walls, and
there are conditions for the formation of ascending nociceptive impulses.

motor function of the gastrointestinal tract determined by the activity
smooth muscle cells, in direct proportion to the concentration of cytosolic Ca
^{2 +} . Calcium ions, activating
intracellular bioenergetic processes (protein phosphorylation, the conversion of ATP into cAMP
, etc.) contribute to the connection actin and myosin that
provides reduction of muscle fibers. One of the prerequisites for
reduce the muscle fiber is a high activity of phosphodiesterase,
which is involved in the cleavage of cAMP and energy supply processes compound
actin-myosin.

in the regulation Transport of calcium ions involved a number of neurogenic mediators:
acetylcholine, catecholamines (norepinephrine), serotonin, cholecystokinin, motilin and
etc. The binding of acetylcholine to the M-cholinergic receptors contributes to the opening
sodium channels and the entry of sodium ions into the cell. Last
reduces the electric potential of the cell membrane (depolarization phase) and leads to
opening of calcium channels through which calcium ions enter the cell,
causing muscle contraction.

Serotonin has a significant effect on motility of the gastrointestinal tract
, activating a number of receptors localizing to the effector cells.
There are several receptor subtypes (5-MT1-4), but the most studied 5-MT3
and 5-MT4. The binding of serotonin with 5-MT3 promotes relaxation, and a 5-MT4 -
reduce muscle fiber. At the same time, mechanisms of action of serotonin on
muscle fibers of the gastrointestinal tract is not fully installed. There
only assumptions about the involvement in these processes of acetylcholine.

tachykinins, which include three types of peptides (substance P,
neurokinin A and B), by contacting the appropriate receptors myocytes , increase
their motor activity, not only as a result of direct activation, but also because
release of acetylcholine. A role in the regulation of motor function of the intestine play
endogenous opiates. When you link them with the