Everything that happens in the human body is subject to certain laws. They act stereotypically regardless of the situation, therefore, the body, trying to defend itself against a “threat” in the form of a medicine or vaccination, sometimes harms itself. Why is this happening? And how can you influence this process in order to turn it to your own good? Is there a concept of a typical pathological process, types that combine properties? Scientists and doctors have been pondering these questions for hundreds of years. They are trying to derive patterns in the reactions of the body in order to analyze its work.
Definition
A typical pathological process is a cascade of sequential reactions that occur in the body in response to the influence of an external or internal factor that disrupts the normal course of life processes. Any pathological process has such qualities as universality, stereotype, polyetiologicality, autochthonousness, equifinality, and clear ontogenetic dynamics.
Knowing the characteristic features allows us to distinguish typical pathological processes from the entire abundance of reactions that occur in the body every minute.
The main characteristics of the pathological process
Typical pathological processes are characterized by the presence of six specific qualities.
- Stereotype. The presence of features of a typical process, regardless of the cause of its appearance and localization.
- Universality. A typical pathological process may be part of different nosological units.
- Polyetiological. The etiological factor of the disease performs only a starting role and is not constant.
- Autochthonism. The property of the process to develop independently, even when the etiological factor ceases to act.
- Equifinality. Different ways of implementing the pathological process, which lead to the same development and resolution.
- Ontogenetic dynamics. This is an improvement in the mechanisms of regulation and the course of the pathological process.
Knowing these characteristics, you can identify any typical pathological processes. Examples of such phenomena: inflammation, fever, hypoxia, stress, shock. In addition, tumor, thrombosis, atrophy, and many others can be attributed to these processes.
Inflammation
Inflammation is a typical pathological process, which is manifested by a change in blood circulation, increased vascular permeability in combination with cell proliferation and dystrophy of surrounding tissues. It is aimed at eliminating a pathogenic irritant and restoring the function of tissues and organs.
Inflammation includes five essential components: fever, pain, swelling, redness, and impaired function. These signs of a typical pathological process can be used for diagnosis, as well as differentiation of nosological units. The mechanism of inflammation is common to all living organisms, including protozoa, regardless of the trigger factor and structural features of the body.
Any inflammation necessarily goes through three stages, which can be more or less pronounced. The first stage is alteration. It is associated with damage to tissues and cells of the body. The exudation following it begins when fluid begins to flow from the vascular bed into the damaged area. And the last stage is proliferation. This is an active reproduction of cells and tissue repair (regeneration).
Fever
Typical pathological processes also include fever and oxygen starvation. You can start with a fever. It is characterized by a persistent increase in body temperature due to changes in the thermoregulation system. Evolutionarily, this reaction was formed to protect the body from infectious agents that died under the influence of high temperature.
A couple of centuries ago, all the diseases in the process of development of which the temperature rose were called “fever”. This term is still present in the name of some nosological units, but by no means everywhere.
The essence of this phenomenon is that the body after entering the pathogen produces specific substances - pyrogens. These chemical compounds affect the thermoregulation center and shift the set point of the temperature constant higher than usual. But the mechanisms of thermoregulation themselves retain their functions. This is a fundamental difference between fever and hyperthermia, during which there is a breakdown of the compensatory mechanisms of thermoregulation.
Hypoxia
Hypoxia is a typical pathological process that occurs due to a lack of oxygen in the air or due to a violation of its delivery to organs and tissues.
Distinguish:
- hypoxic hypoxia (decrease in oxygen pressure in the ambient air);
- respiratory or respiratory (violation of oxygen transport through the blood-alveolar barrier);
- hemic, otherwise blood (decreased blood capacity for oxygen molecules);
- circulatory (decrease in blood circulation intensity);
- tissue (decreased oxygen perception by tissues);
- reloading (organ cell membranes are functionally overloaded);
- mixed;
- technogenic (develops if the body is in a medium with a high content of smog for a long time).
The most sensitive to oxygen deficiency are nerve tissue, heart muscle, liver and kidney cells. To correct hypoxia, drugs are used that increase oxygen delivery to tissues or reduce the body's need for this gas.
Allergy
The concept of typical pathological processes cannot do without mentioning allergies. This is a hypersensitive reaction of the body's immune system to the appearance of antigens in the body. Four types of hypersensitivity are distinguished:
- Anaphylactic. During the first contact of the body with the antigen, a lot of immunoglobulin E is formed, which attaches to mast cells and circulates in the blood. Upon repeated contact with the antigen, mast cells are destroyed, inflammatory mediators that cause a systemic reaction enter the blood and tissues.
- Cytotoxic. The antigen located on the cell membrane is captured by immunoglobulins of classes M and G. After this, the cell is destroyed by phagocytosis, either under the influence of complement proteins, or natural killers.
- Immunocomplex. Antibodies firmly bind to antigens and attach to the walls of blood vessels. Vascular endothelial cells are destroyed by the action of released enzymes.
- Delayed hypersensitivity (HRT). When an antigen enters the body, it interacts with macrophages and T-helpers, stimulating the immune system.
Stress
Stress is a collective concept that includes non-specific adaptive mechanisms of the body, which are activated by various external and internal factors. Allocate positive stress - eustress, and negative - distress. According to the type of exposure, neuropsychic, temperature, light, hunger, and other stresses are distinguished.
Physiological stress is otherwise referred to as General Adaptation Syndrome (OSA). Physiologist Hans Salier found that, in addition to compensating for the stress state, damage to some elements of the body is also observed: a decrease in the thymus gland, an increase in the adrenal cortex, and ulcers of the gastrointestinal tract.
The same scientist identified three stages of OSA:
- anxiety (mobilization of body reserves);
- resistance;
- exhaustion.
Five years after the publication of his theory, in 1938, Salier proposed a theory of short-term and long-term adaptation.
Thrombosis
Typical pathological processes associated with circulatory disorders are hypoxia and thrombosis. The latter is the formation of blood bundles inside the vessels during human life. After damage to the artery, vein, capillary or any other vessel, platelets rush to the rupture site, which are glued together by fibrin and form the primary thrombus. It blocks the defect and stops the loss of blood from the vascular bed.
This is the positive side of the process. But under certain conditions (massive blood loss, disruption of adaptation mechanisms, increased lipid content), blood clots can form without damage to the bloodstream. Clots circulate through the bloodstream and can clog small (or large) vessels, causing ischemia and organ necrosis.
There are three factors contributing to the development of thrombosis, the so-called. the triad of Virchow:
- hypercoagulation, or thrombophilia (a condition caused by genetic defects or increased readiness of the immune system);
- damage to vascular mucosa cells (injuries, surgery, infections);
- blood flow disturbance at the site of damage (blood stasis due to cardiovascular failure).
Tumor
Medical science allows us to consider the tumor as a typical pathological process. The definition of this concept is as follows: this is tissue that was formed as a result of changes in the genetic apparatus of the cell. These changes led to a violation of their growth and differentiation.
All tumors are divided into two large groups: benign and malignant. There are five features inherent in all tumors:
- atypism (tissue or cell);
- organoid structure;
- progression;
- autonomy;
- unlimited growth.
For benign slow growth is characteristic. They do not form metastases and do not have a negative effect on the body as a whole. But with a combination of adverse circumstances, the tumor can become malignant.
Atrophy
Typical pathological processes include atrophy and dystrophy. Atrophy is a decrease in the size of organs and tissues due to an eating disorder. During atrophy, a decrease in the thickness of muscle fibers, a decrease in the amount of actin and myosin, plastic substances. Sections of necrosis appear in the myocardium, and ulcers appear on the gastric mucosa. Atrophy develops when a person is exhausted by a long illness or is forced to observe strict bed rest, for example after a fracture or heart attack.
The effects of atrophy can be easily corrected if motor activity is restored in a timely manner. Therefore, in surgery it is customary to lift the patient in the postoperative period, in intensive care - to engage in physiotherapy and breathing exercises.
In a non-medical sense, this word is used when they want to focus on the loss of any feeling or ability.
Dystrophy
Dystrophy is a typical pathological process characterized by metabolic disturbance at the tissue level, which leads to their structural changes. At the heart of this process is a malnutrition of cells. The mechanisms of trophic tissue and organs are divided into intracellular and extracellular.
Intracellular mechanisms include:
- transport of metabolic products through blood and lymph;
- intercellular mesenchyme;
- neuroendocrine regulation.
Violation of each link individually or all together causes a particular type of dystrophy. Protein, fat, carbohydrate and mineral dystrophy are distinguished, as well as chronic.
Atherosclerosis
Violation of lipid metabolism is also included in typical pathological processes. The pathophysiology of this condition is associated with impaired metabolism of fats and their deposition in the walls of blood vessels. Low and very low density lipids infiltrate endothelial cells, forming atheromatous plaques. At the next stage, in their place, connective tissue grows, which is absorbed by calcium ions. The walls of the vessel are deformed, narrowed and can become completely clogged. This leads to ischemia and impaired organ function.