Stasis is a pathological condition: its causes and types
Movement of blood through the vessels is a complex physiological process that provides nutrition to all organs and helps to ensure the continuity of the internal environment. Vessels are classified according to their size in order of magnitude: from the first order( the largest ones) to the second, third, and end with capillaries. The network of the latter permeates all the organs and skin, which contains them in huge numbers.
Pathological impairment of blood supply to vessels
Environmental and internal factors affect the movement of blood flow effect, which can be manifested by violations of the patency of vessels due to the aggregation of uniform elements. One such process is stasis. This is a condition in which the microcirculatory pathway is disturbed or slowed down. In the manifestation of stasis, capillaries and venules expand to form homogeneous columns of erythrocytes, but hemolysis and thickening of the blood are not observed.
Stasis is a reversible process, accompanied by dystrophic changes in the nutrition of tissues and organs. A prolonged and persistent disruption of the supply of beneficial substances can lead to irreversible phenomena and cause necrosis.
Conditions of occurrence and course of stasis
The process of stasis is the activation of proaggregants, cations and high-molecular proteins. Proagregants cause gluing, attachment to the walls of the vessels and destruction of the shaped elements with a complete change in them. These components include catecholamines, thromboxane A2.
Cations released from cells of blood, vessels and tissues are absorbed by the intracellular membrane of the element elements, and their excess on it neutralizes their negative charge. The cations of these cells are mainly represented by K +, Na +, Ca +, Mg2 +.
High-molecular proteins are combined with negatively charged membrane ions by amino groups and neutralize them by their positive charge, creating conditions for attaching the element elements to the walls of the vessels and sticking together. Proteins that potentiate the element are gamma globulins and fibrinogen.
Types of stasis
There are several types of stasis depending on the system where it occurs. But in the blood system, the pathological process is characterized by a violation in the arterial and venous blood supply. Primary, ischemic and congestive stasis is distinguished.
- The primary stasis is the activation of proagregants with uniform elements of blood and the violation of patency in the lumen of the vessels by them, which causes hypoxic starvation of the tissue or part of the organ.
- Ischemic stasis - a violation of outflow or arterial blood supply due to the destruction of the formed elements and the occurrence of obstruction of the microvessel.
- Congestive stasis or venous stasis occurs when the rheological properties of the blood are violated and helps to slow the outflow of blood from the microvessels by closing the lumen of the vessels.
External causes of stasis formation
Among the external causes, the following are distinguished:
- Stasis is formed as a result of plethora, which increases vascular permeability and causes aggregation and gluing of the shaped elements.
- Intoxication with drugs or endotoxins of microorganisms provokes the release of active substances.
- Exposure to physical factors such as cold, heat and noise.
Blood clotting or hemostasis
Hemostasis is a physiological process that stops bleeding when the integrity of the vessel is disturbed at the local level. Its main function is to maintain the constancy of the internal environment of the body. According to the conditions and mechanisms, it is a complex biological system in which uniform elements, the vascular wall, humoral mechanisms, plasma and tissue mechanisms of the coagulation system of blood take part. Violation of the components of hemostasis in the work leads to a violation of blood coagulability.
Consider a small example. Violation of the integrity of the skin leads to vascular disruption and the appearance of bleeding. This leads to the formation of stasis of blood in the wound due to the formation of filaments of fibrin. In this case, the main components of hemostasis are involved.
The blood coagulation system is reduced for several reasons, which may be due to acquired or hereditary factors. In the first case, the causes of hemostasis disorders are immune reactions under the influence of viruses and medicinal substances, which causes a change in the antigenic structure of platelets. Also, the effects of ionizing radiation, bone marrow malfunction and chemotherapy of tumor formations are the cause of thrombocytopenia. Increased permeability of the walls of the vessels, a disorder of collagen synthesis lead to increased bleeding.
An example of hereditary disorders is hemophilia, which is betrayed through the male line, and to compensate for it, it is necessary to replenish the missing protective factors with the help of medications in the body.