The capillary wall consists of three layers of cells:
1. The endothelial layer consists of polygonal cells of various sizes. There are villi on the luminal (facing the lumen of the vessel) surface, covered with glycocalyx, which adsorbs and absorbs metabolic products and metabolites from the blood.
Endothelial functions:
Atrombogenic (synthesize prostaglandins that prevent platelet aggregation).
Participation in the formation of the basement membrane.
Barrier (it is carried out by the cytoskeleton and receptors).
Participation in the regulation of vascular tone.
Vascular (synthesize factors that accelerate the proliferation and migration of endothelial cells).
Synthesis of lipoprotein lipase.
2. A layer of pericytes (process-shaped cells containing contractile filaments and regulating the lumen of capillaries), which are located in the fissures of the basement membrane.
3. A layer of adventitial cells embedded in an amorphous matrix, in which thin collagen and elastic fibers pass.
Classification of capillaries
1. By lumen diameter
Narrow ones (4-7 microns) are found in transversely striated muscles, lungs, and nerves.
Wide (8-12 microns) are found in the skin and mucous membranes.
Sinusoidal (up to 30 microns) are found in the hematopoietic organs, endocrine glands, and liver.
Lacunae (more than 30 microns) are located in the columnar zone of the rectum and the cavernous bodies of the penis.
2. According to the structure of the wall
Somatic, characterized by the absence of fenestrae (local thinning of the endothelium) and holes in the basement membrane (perforations). Located in the brain, skin, muscles.
Fenestrated (visceral type), characterized by the presence of fenestrae and the absence of perforations. They are located where molecular transfer processes occur especially intensively: glomeruli of the kidneys, intestinal villi, endocrine glands).
Perforated, characterized by the presence of fenestrae in the endothelium and perforations in the basement membrane. This structure facilitates the passage through the wall of the capillary cells: sinusoidal capillaries of the liver and hematopoietic organs.
Capillary function– the exchange of substances and gases between the lumen of the capillaries and surrounding tissues is carried out due to the following factors:
1. Thin wall of capillaries.
2. Slow blood flow.
3. Large area of contact with surrounding tissues.
4. Low intracapillary pressure.
The number of capillaries per unit volume varies in different tissues, but in each tissue there are 50% non-functioning capillaries that are in a collapsed state and only blood plasma passes through them. When the load on the organ increases, they begin to function.
There is a capillary network that is enclosed between two vessels of the same name (between two arterioles in the kidneys or between two venules in the portal system of the pituitary gland); such capillaries are called the “miraculous network.”
When several capillaries merge, they form postcapillary venules or postcapillaries, with a diameter of 12 -13 microns, in the wall of which there is fenestrated endothelium, more pericytes. When postcapillaries merge, they form collecting venules, in the middle membrane of which smooth myocytes appear, the adventitial membrane is better expressed. Collecting venules continue into muscle venules, the middle shell of which contains 1-2 layers of smooth myocytes.
Function of venules:
1. Drainage (flow of metabolic products from the connective tissue into the lumen of the venules).
2. Blood cells migrate from the venules into the surrounding tissue.
The microvasculature consists of arteriolo-venular anastomoses (AVA)- these are vessels through which blood from arterioles enters venules bypassing capillaries. Their length is up to 4 mm, diameter more than 30 microns. AVAs open and close 4 – 12 times per minute.
ABAs are classified into true (shunts), through which arterial blood flows, and atypical (half shunts) through which mixed blood is discharged, because When moving along the half-shunt, a partial exchange of substances and gases occurs with the surrounding tissues.
Functions of true anastomoses:
1. Regulation of blood flow in capillaries.
2. Arterialization of venous blood.
3. Increased intravenular pressure.
Functions of atypical anastomoses:
1. Drainage.
2. Partially exchangeable.
AND arteries, capillaries take part in between tissues and blood. Since the walls of capillaries consist of a single layer endothelium, the thickness of which is very small, they can pass through lipids, water, oxygen molecules and some other substances. In addition, waste products (such as urea and carbon dioxide) can also pass through the capillary walls, which transport substances for elimination through the body. Special molecules affect the permeability of the capillary wall.
Also among the important functions of the endothelium is the transport of messenger substances, nutrients and other compounds. Sometimes molecules are too large to penetrate the wall by diffusion, then other mechanisms are used to transport them - exocytosis and endocytosis. The walls of capillaries are highly permeable to all low molecular weight substances dissolved in.
Due to the capillary network, such an important process as blood circulation of organs. The need for capillaries to provide nutrients depends on the metabolic activity of the molecules. Under normal conditions, the capillary network is provided with only a quarter of the volume of blood that it can accommodate. But self-regulatory mechanisms that work by relaxing smooth muscle cells can increase this volume even more. But it should be noted that any increase in the lumen of the capillary is passive, since the wall does not contain muscle cells. Signaling substances that are synthesized by the endothelium affect the muscle cells of large vessels located in the immediate vicinity.
There are several types of capillaries:
- Continuous capillaries
- Fenestrated capillaries
- Sinusoidal capillaries
For continuous capillaries characterized by very dense intercellular connections that allow only small ions and molecules to diffuse.
Fenestrated capillaries are located in the endocrine glands, intestines and other internal organs, in which active transport of substances takes place between surrounding tissues and blood. The walls of such capillaries have gaps that allow large molecules to penetrate.
Sinusoidal capillaries can be found in hematopoietic and endocrine organs, such as the spleen and, in lymphoid tissue, the liver. Such capillaries, located in the hepatic lobules, contain Kupffer cells, which can destroy and capture foreign bodies. Sinusoidal capillaries are characterized by the fact that they contain slits (sines), the size of which is sufficient for the penetration of large protein molecules and molecules outside the lumen of the capillary.
Interesting Facts
- The total length of an adult's capillaries is enough to wrap around the Earth twice.
- The total cross-sectional area of these thin vessels is about fifty square meters, which is 25 times the surface of the body.
- There are about 100-160 billion capillaries in the adult human body.
Program
“Healthy capillaries” http://www.64z.ru/capillaries/
Health after forty, and by and large life expectancy, is determined by the health of the capillaries.
What are capillaries
Capillaries (from the Latin capillaris - hair) are the thinnest vessels in the human body; they penetrate all tissues, forming a wide network of interconnected vessels that are in close contact with cellular structures; they supply cells with necessary substances and carry away waste products. The arterial part of the capillaries squeezes the water of the blood plasma through its walls. The venous portion absorbs water from extracellular fluids. This is the essence of the circulation of organic fluids in the body.
From anatomy it is known that the walls of capillaries consist of individual, closely adjacent and very thin endothelial cells. The thickness of this layer is so thin that it allows molecules of oxygen, water, lipids and many others to pass through it. Products produced by the body (such as carbon dioxide and urea) can also pass through the capillary wall to transport them to the site of elimination from the body.
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Capillary endothelial cells selectively retain some chemicals and allow others to pass through. Being in a healthy state, they allow only water, salts and gases to pass through them. If the permeability of capillary cells is impaired, then other substances enter the tissue cells, as a result of which the cells die from metabolic overload. Capillaropathy is a violation of the permeability of capillary walls.
Properties of capillaries
A capillary is a nanotube, shaped like a cylinder with a diameter of 2 to 30 microns, formed by one layer of endothelial cells. The average diameter of a capillary is 5-10 microns (the diameter of a red blood cell is approximately 7.5 microns). The length of a single capillary averages from 0.5 to 1 mm. The wall thickness ranges from 1 to 3 microns. Capillaries are formed by endothelial cells connected to each other by “intercellular cement” and forming a tube. The pores of the capillary wall have a diameter of about 3 nm, sufficient to ensure the diffusion of fat-insoluble molecules ranging in size from the size of a sodium chloride molecule to the size of a hemoglobin molecule. Fat-soluble molecules diffuse through the thickness of capillary endothelial cells. Diffusion of oxygen and carbon dioxide occurs through any sections of the capillary wall.
Each capillary has an arterial section, an expanded transitional section and a venous section.
At the two ends of the capillary there are narrowings - analogues of heart valves. At the point where the capillary departs from the precapillary arteriole, there is a precapillary sphincter, which is involved in regulating blood flow through the capillary.
The walls of the capillaries do not contain a muscle layer and are therefore physically incapable of contraction. But they contract, reacting to the pulsation of the energy of the heart and adapting to its rhythm. Therefore, capillaries are able to contract rhythmically and push blood through. It is systole, because contractions of capillaries are the essence of blood circulation.
Capillaries are the storage of energy in the body. The energy intensity of the physical body is determined by the state of the capillaries.
Capillaries
Capillaries and heart
Based on the above, capillaries can be called peripheral hearts, associating them with the physical heart. Another thing is that the traditionally perceived role of the heart as a blood pump does not correspond to the actual one. The task of the heart is to recognize and differentiate blood flow depending on its quality. The purpose of the heart is to send each organ, each system the portion of blood that they need in quantity and quality. The heart divides the general flow of blood passing through it into separate vortices, fundamentally different in their content. The second purpose of the heart is to set the rhythm of vital activity of the whole organism. First of all, setting the rhythm of the capillary network. Heart research is the topic of another work. Here we need to trace the connection between the heart, blood vessels and capillaries.
The heart gets overloaded when the capillaries do not have time to change the rhythm of their activity in accordance with the new rhythm that the heart sets. For example, with a rapid transition from the passive state of the physical body to the mode of its active activity. Or when you suddenly stop after serious physical activity. A smooth change in the degree of activation of the physical body allows for better synchronization of the work of the cardiovascular and circulatory systems.
The task of the heart is to set the rhythm for all physiological processes in the body, i.e. the speed and consistency of their occurrence. In terms of this topic, the heart sets the rhythm and force of contraction of the capillaries and thereby determines the number of capillaries that are actively functioning at the moment. Heart rhythm disturbances are largely associated with capillary circulation disorders.
Many diseases of the cardiovascular system, incl. associated with cardiac arrhythmias are treated by restoring capillary circulation. Those. restoration of the throughput and filtering abilities of capillaries, as well as restoration of their ability to rhythmically pulsate, automatically restores the functionality of the heart and normalizes its rhythm. This is why Zalmanov’s turpentine baths are so effective for many disorders of the cardiovascular system, although ignorant experts call these disorders contraindications to Zalmanov’s turpentine baths.
The metabolism of all substances in the body depends on the movement of blood in the capillary network. It is through capillaries that the most important processes of nutrition and cell cleansing occur. The task of the heart is to direct blood of the appropriate quality and in the required quantity to all organs and systems. The purpose of the vessels is to bring blood from the heart to the capillaries. The task of capillaries is to ensure metabolism in each cell.
The functioning of the heart and blood vessels is largely determined by the state of the capillary network that penetrates them, i.e. capillaries of blood vessels and capillaries of the heart.
Impaired capillary circulation underlies diseases of the physical body. It leads to a mismatch between the interactions of a part of the organism and the whole organism. If we decide that life is a part, united with the whole, then we will reveal the most important dependence of life, as such, on the state of capillary blood circulation.
Any disease is associated with a slowdown or cessation of blood circulation in some place in the body. Any disease is also associated with a slowdown in the movement of intercellular fluids.
Using capillaroscopy, it was found that at the age of 40-45 years, the number of open capillaries begins to decrease. The reduction in their number is constantly progressing and leads to drying out of cells and tissues. Progressive drying of the body constitutes the anatomical and physiological basis of its aging. If you do not counteract this with special actions, then the time comes for arteriosclerosis, hypertension, angina pectoris, neuritis, joint diseases and many other diseases.
Stagnation of blood in capillaries and vessels opens up the possibility of invasion of various microbes. Pure blood, actively moving blood naturally helps disinfect the body.
A sharp narrowing of the capillaries of the ear labyrinth - the organ of balance - leads to dizziness, nausea, vomiting, weakness, and pallor. Spasm of cerebral capillaries causes ischemia and dizziness. In people with glaucoma, you can see various painful changes in the skin capillaries. With urticaria, there is a sharp painful expansion of the capillaries of the skin. At the beginning of the development of hemorrhagic nephritis, massive narrowing of the capillaries occurs. A disease of pregnant women - eclampsia - develops as a result of stagnation of blood in the capillaries of the uterus, peritoneum and skin.
With all joint diseases, there is stagnation of blood in the capillary network. Without such stagnation, there is no arthritis, no arthrosis, no deformation of joints, tendons, bones; There is no muscle atrophy.
Congestion in the capillaries is detected after cerebral strokes, with angina pectoris, scleroderma, lymphostasis, and cerebral palsy.
With the development of gastric or duodenal ulcers, capillary spasms also play a primary role. Capillaries supply blood to the mucous membranes and submucosal membranes, and their spasms lead to a lack of oxygen in the cells and the formation of many micronecrosis in the mucous membranes and submucosal membranes. If the foci of micronecrosis are scattered, then a diagnosis of gastritis is made - inflammation of the gastric mucosa. If the foci of micronecrosis merge, a stomach or duodenal ulcer is formed.
Obvious signs by which you can determine the condition of the capillaries
Do a test showing the functional state of your capillaries: run your fingernail across your body with force. As a mark, a white stripe will remain, which should turn pink after a few seconds. White skin color - under external pressure the blood has left the capillaries; red color of the skin - the capillaries are filled with blood in excess. The shorter the period of time during which the skin color changes, the better the capillaries work. In this case, the effect should be observed in a matter of seconds.
A more serious test of capillary capacity is the body's reaction to cold. The colder the environment, the more the body must warm up. We are not talking about long-lasting cooling, but about a sharp change in temperature. For example, brief immersion in cold water should cause fever, not chills. A contrast shower is an excellent tool for training the entire vascular system.
If household injuries lead to the formation of hematomas - bruises - this is a sure indicator of capillary fragility. Hemorrhage in the eye also indicates the fragility of the capillaries. The fragility of capillaries can lead to internal hemorrhages with subsequent tissue degeneration in any part of the body, in any organ. Heart attack and stroke are common results of ruptured weak and inelastic capillaries.
Abnormal skin color, numbness, sweating of the extremities, a feeling of coldness in them, unpleasant sensations in the form of tingling, burning, crawling, various skin rashes and spots, as well as sclerosis and atrophy of soft tissues are manifestations of poor blood circulation in the precapillary arterioles, post capillary venules and in the capillaries themselves.
Necessary conditions for capillary restoration
Drinking enough clean water.
Thick and dirty blood is the most common cause of capillaropathy. An elementary action - daily consumption of high-quality water in sufficient quantities - is currently not available to most people, either for objective or subjective reasons. In conditions of chronic dehydration, there is no point in talking about restoring capillaries. Therefore, it is so rare to meet a person whose capillaries are healthy.
For information on the rules of water consumption, see the health program “Restoring Health with Water”
Physiologically correct spatial position of the body.
The position of the body in space always leaves a specific imprint on the work of its systems and organs, stimulating the blood supply to some and inhibiting the blood supply to others. We are talking primarily about correct posture when we walk, stand or sit.
The posture corrector vest-simulator “Dobrynya” trains, trains muscles, develops correct muscle memory, setting the ideal position of the spine.
The Asonia orthopedic pillow allows, during rest and sleep, firstly, to assume a physiologically correct position for the cervical spine, and secondly, it prevents disruption of the capillary circulation of the part of the head that touches the pillow. It is the capillaries of the facial skin that are inactive under the pressure of body weight during sleep that are one of the main causes of wrinkles and aging of the skin. Asonia creates the effect of pseudo-weightlessness, and the capillaries act normally during sleep.
Morning exercises, evening cross-country, swimming pool, gym or an energetic walk instead of transport - choose to suit your taste. In this case, the very fact of physical activity as such is important. Its type, intensity and duration are a secondary matter.
The lack of necessary conditions contributes to the degradation of the circulatory system.
Methods for restoring capillaries
Zalmanov’s turpentine baths are the best and most affordable known practice for restoring capillaries and reducing biological age. The best known turpentine for Zalmanov’s baths is Skipofit. Pay special attention to Skipofit. This is truly the most effective remedy for training capillaries and general rejuvenation of the body. Turpentine baths awaken capillary blood circulation throughout the body at once. You will not achieve such a healing result with any locally applied remedy.
Contrast water (air) procedures. The most affordable options are contrast showers and baths. Information on how to properly take a contrast shower.
Polimedel improves the functioning of capillaries in an area up to 10 cm deep into the body.
Propolis Heliant fundamentally cleanses the capillaries of the skin. Both Polimedel and Propolis Heliant not only stimulate existing capillaries, but revive the capillary network, causing new capillaries to grow into those areas of connective tissue where there were none, for example, in scars.
All inverted body positions, i.e. such positions in which the pelvis is higher than the head. The best physical exercise for restoring capillary blood circulation and for training blood vessels is a headstand. The healing power of headstand, as a way to prevent many cardiovascular pathologies - heart attack, stroke, varicose veins, atrophy of the capillary network, etc., is very great. Therefore, you must approach this exercise with extreme caution, starting with simpler inverted poses.
Physical exercise.
In the vascular walls, at the point where the capillaries branch from the arterioles, there are clearly defined rings of muscle cells that play the role of sphincters that regulate the flow of blood into the capillary network. Under normal conditions, only a small part of these so-called ones is open. precapillary sphincters, so that blood flows through few of the available channels.
The greater the metabolic activity of cells, the more functioning capillaries are required to ensure their vital activity. The fact is that in a person at rest, capillaries function only a quarter. The remaining three quarters are reserve capabilities that are activated in response to physical activity. Capillaries are 100% activated at moments of highest tension in muscles and organs.
It is necessary that the capillaries, which are not used in a calm state of the body, are periodically put into operation. These support the body's reserve functional and energy resources.
Superfood – Living cocoa.
It has been proven that the substances contained in living cocoa have a strengthening effect on capillaries. Live cocoa prevents the development of atherosclerosis and reduces the risk of cardiovascular diseases.
Live cocoa stimulates blood flow to the brain, in particular to those areas of the brain that are responsible for reaction speed and memory. The experiments carried out suggest that living cocoa restores elasticity to blood vessels so that they become 10-15 years younger, and the elasticity of blood vessels is a guarantee against early hypertension and heart attacks and strokes. Researchers have found that the risk of stroke is reduced by 8 times, heart failure by 9 times, cancer by 15 times and diabetes by 6 times with daily consumption of live cocoa.
Biologically active food additives.
The best known biologically active food additives that normalize capillary blood circulation:
Balsam Polifit-M is a microemulsion of fermented oils and juices of fresh plants. Polifit-M works especially well with blood vessels and capillaries of the brain.
Ovodorin is an extract of the mycelium of a medical variety of oyster mushroom.
Oleksin is a powerful natural remedy made from peach tree leaves.
Marcello Malpighi(Italian biologist and physician) discovered capillaries in 1678, thereby completing the description of a closed vascular system.
Hemocapillaries, depending on which organs they are located in, they can have different diameters.
The smallest capillaries(diameter 4-7 microns) are found in striated muscles, lungs, and nerves;
wider capillaries(diameter 8-11 microns) - in the skin and mucous membranes;
even wider capillaries - sinusoids(diameter 20-30 microns) are located in the hematopoietic organs, endocrine glands, liver;
the widest capillaries-gaps(diameter more than 30 microns) are located in the columnar zone of the rectum and in the cavernous bodies of the penis.
Capillaries intertwining with each other form a network. In addition, they can have the shape of a loop (in the intestinal villi, skin papillae, villi of joint capsules). The end of the capillary that arises from the arteriole is called arterial, and which flows into the venule - venous. The arterial end is always narrower, and the venous end is wider, sometimes 2-2.5 times. The endothelial cells of the venous end have more mitochondria and microvilli.
Capillaries can form glomeruli (in the kidneys). Capillaries can arise from an arteriole and enter an arteriole (the afferent and efferent arterioles of the kidneys) or arise from a venule and enter a venule (the pituitary portal system). If the capillaries are located between two arterioles or two venules, then this is called the miraculous network (rete mirabile).
The number of capillaries per unit volume may vary in different tissues. For example, in skeletal muscle tissue, in a cross-sectional area of 1 mm2, there are up to 2000 sections of capillaries, in the skin - about 40.
Each tissue has approximately 50% of capillaries in reserve. These capillaries are called non-functioning; they are in a collapsed state, only blood plasma passes through them. With an increase in the functional load on the organ, some of the non-functioning capillaries turn into functioning ones.
Wall capillaries consists of 3 layers:
1) endothelium, 2) layer of pericytes and 3) layer of adventitial cells.
Endothelial layer consists of flattened polygonal cells of various sizes (length from 5 to 75 μm). On the luminal surface (the surface facing the lumen of the vessel), covered with the plasmalemmal layer (glycocalyx), there are microvilli that increase the surface of the cells. The cytolemma of endothelial cells forms many caveolae, and in the cytoplasm there are many pinocytotic vesicles. Microvilli and pinocytotic vesicles are a morphological sign of intensive metabolism. At the same time, the cytoplasm is poor in organelles of general importance, there are microfilaments that form the cytoskeleton of the cell, and there are receptors on the cytolemma. Endotheliocytes connect to each other using interdigitations and adhesion zones. Among the endotheliocytes there are fenestrated ones, i.e. endotheliocytes that have fenestrae. Fenestrated capillaries are present in the pituitary gland and glomeruli of the kidneys. ALP and ATPase are found in the cytoplasm of endothelial cells. Endothelial cells at the venous end of the capillary form folds in the form of valves that regulate blood flow.
The functions of the endothelium are numerous:
1) atrombogenic (negative charge of the glycocalyx and synthesis of prostaglandin inhibitors that prevent platelet aggregation);
2) participation in the formation of the basement membrane;
3) barrier, due to the presence of a cytoskeleton and receptors;
4) participation in the regulation of vascular tone, due to the presence of receptors and the synthesis of factors that relax/contract vascular myocytes;
5) vessel-forming, due to the synthesis of factors that accelerate the proliferation and migration of endothelial cells;
6) secretion of lipoprotein lipase and other substances.
basement membrane The capillaries are about 30 nm thick and contain an ATPase. Function of the basement membrane- ensuring selective permeability (exchange), barrier. Some capillaries have holes or slits in the basement membrane.
Pericytes are located in the crevices of the basement membrane and have a branched shape. Their cytoplasm is capable of osmotic swelling - they compress the lumen. The processes contain contractile filaments. The processes of pericytes cover the capillary, and efferent nerve endings end on them. There are contacts between pericytes and endothelial cells. In the place where the contact is located, there is a hole in the basement membrane.
Functions of pericytes:
1) contractile, due to the presence of contractile filaments;
2) supporting, due to the presence of a cytoskeleton;
3) participation in regeneration, thanks to the ability to differentiate into smooth myocytes;
4) control of endothelial cell mitosis due to contacts between pericytes and endothelial cells;
5) participation in the synthesis of basement membrane components, due to the presence of granular EPS.
Adventitial layer represented by adventitial cells embedded in an amorphous matrix around a capillary in which thin collagen and elastic fibers pass.
Classification of capillaries depending on the structure of their wall. Currently, there are 3 types of capillaries:
1st type - continuous lined capillaries, somatic, characterized by the absence of fenestrae in the endothelium and holes in the basement membrane - these are capillaries of skeletal muscles, lungs, nerve trunks, mucous membranes;
2nd type - fenestrated capillaries, characterized by the presence of fenestrae in the endothelium and the absence of holes in the basement membrane - these are the capillaries of the glomeruli of the kidneys and intestinal villi;
3rd type - sinusoidal capillaries, perforated, characterized by the presence of fenestrae in the endothelium and holes in the basement membrane - these are sinusoidal capillaries of the liver and hematopoietic organs, due to their large width (diameter up to 130-150 microns), increased permeability of the wall and slow blood flow in the hematopoietic organs, migration of mature formed elements occurs into the lumen of the sinusoids.
Capillary function - exchange of substances and gases between the lumen of the capillaries and surrounding tissues. This is facilitated by 4 factors:
1) thin wall of capillaries;
2) slow blood flow (0.5 mm/s);
3) large area of contact with surrounding tissues (6000 m2);
4) low intracapillary pressure (20-30 mm Hg).
In addition to these four factors, the intensity of metabolism depends on the permeability of the basement membrane of the capillaries and the ground substance of the surrounding connective tissue. Permeability increases when exposed to histamine and hyaluronidase, which destroys hyaluronic acid, which helps increase metabolism. Snake venom and the venom of poisonous spiders contain a lot of hyaluronidase, so these poisons easily penetrate the body. Vitamin C and Ca 2+ ions increase the density of basement membranes and the main intercellular substance.
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