What is blood made of and what is its role in the human body. MedAboutMe - Human blood: composition, examinations, pathologies Blood plasma: composition and properties
Peripheral blood consists of a liquid part - plasma and shaped elements suspended in it, or blood cells(erythrocytes, leukocytes, platelets) (Fig. 2).
If you let the blood stand or centrifuge it, having previously mixed it with an anticoagulant, then two layers that differ sharply from each other are formed: the upper one is transparent, colorless or slightly yellowish - blood plasma, the lower one is red, consisting of erythrocytes and platelets. Due to the lower relative density, leukocytes are located on the surface of the lower layer in the form of a thin white film.
The volumetric ratios of plasma and formed elements are determined using a special device hematocrit- a capillary with divisions, as well as using radioactive isotopes - 32 P, 51 Cr, 59 Fe. In the peripheral (circulating) and deposited blood, these ratios are not the same. In the peripheral blood, plasma makes up approximately 52-58% of the blood volume, and formed elements - 42-48%. The reverse ratio is observed in the deposited blood.
Blood plasma, its composition. Blood plasma is a rather complex biological environment. It is in close connection with the tissue fluids of the body. The relative plasma density is 1.029-1.034.
The composition of blood plasma includes water (90-92%) and dry residue (8-10%). The dry residue consists of organic and inorganic substances. Organic substances in blood plasma include:
1) plasma proteins - albumins (about 4.5%), globulins (2-3.5%), fibrinogen (0.2-0.4%). The total amount of protein in plasma is 7-8%;
2) non-protein nitrogen-containing compounds (amino acids, polypeptides, urea, uric acid, creatine, creatinine, ammonia). The total amount of non-protein nitrogen in plasma (the so-called residual nitrogen) is 11-15 mmol / l (30-40 mg%). If the function of the kidneys, which excrete toxins from the body, is impaired, the content of residual nitrogen in the blood increases sharply;
3) nitrogen-free organic substances: glucose - 4.45-6.65 mmol / l (80-120 mg%), neutral fats, lipids;
4) enzymes; some of them are involved in the processes of blood coagulation and fibrinolysis, in particular prothrombin and profibrinolysin. Plasma also contains enzymes that break down glycogen, fats, proteins, etc.
Inorganic substances of blood plasma make up about 1% of its composition. They mainly include cations - Na + , Ca ++ , K + , Mg ++ and anions - O - , HPO 4 - , HCO 3 - .
From the tissues of the body in the process of its vital activity, it enters the blood a large number of metabolic products, biologically active substances(serotonin, histamine), hormones, nutrients, vitamins, etc. are absorbed from the intestines. However, the composition of the plasma does not change significantly. The constancy of the plasma composition is ensured by regulatory mechanisms that affect the activity of individual organs and systems of the body, restoring the composition and properties of its internal environment.
Osmotic and oncotic blood pressure. Osmotic pressure is the pressure that is caused by electrolytes and some non-electrolytes. with low molecular weight (glucose, etc.). The higher the concentration of such substances in the solution, the higher the osmotic pressure. The osmotic pressure of plasma depends mainly on the concentration in it mineral salts and averages 768.2 kPa (7.6 atm). About 60% of the total osmotic pressure is due to sodium salts. Plasma oncotic pressure is due to proteins that are able to retain water. The value of oncotic pressure ranges from 3.325 to 3.99 kPa (25-30 mm Hg). The value of oncotic pressure is extremely high, since due to it the liquid (water) is retained in the vascular bed. Of the plasma proteins, albumins take the greatest part in providing oncotic pressure, since, due to their small size and high hydrophilicity, they have a pronounced ability to attract water to themselves.
The functions of body cells can only be carried out with the relative stability of osmotic and oncotic pressure (colloidal osmotic pressure). The constancy of the osmotic and oncotic blood pressure in highly organized animals is a general law, without which their normal existence is impossible.
If erythrocytes are placed in saline solution having the same osmotic pressure as blood, they notable changes are not exposed. When red blood cells are placed in a solution with high osmotic pressure, the cells shrink as water begins to escape from them into the environment. In a solution with low osmotic pressure, red blood cells swell and break down. This happens because water from a solution with low osmotic pressure begins to enter the erythrocytes, the cell membrane cannot withstand high blood pressure and bursts.
A saline solution having an osmotic pressure equal to the blood pressure is called iso-osmotic, or isotonic (0.85-0.9% NaCl solution). A solution with a higher osmotic pressure than blood pressure is called hypertonic, and having a lower pressure - hypotonic.
Hemolysis and its types. Hemolysis called the exit of hemoglobin from erythrocytes through a modified membrane and its appearance in plasma. Hemolysis can be observed both in the vascular bed and outside the body.
Outside the body, hemolysis can be induced by hypotonic solutions. This type of hemolysis is called osmotic. A sharp shaking of the blood or its mixing leads to the destruction of the erythrocyte membrane. In this case, it happens mechanical hemolysis. Some chemical substances(acids, alkalis; ether, chloroform, alcohol) cause coagulation (denaturation) of proteins and disruption of the integral membrane of erythrocytes, which is accompanied by the release of hemoglobin from them - chemical hemolysis. The change in the shell of erythrocytes with the subsequent release of hemoglobin from them also occurs under the influence of physical factors. In particular, when acting high temperatures denaturation of erythrocyte membrane proteins is observed. Freezing the blood is accompanied by the destruction of red blood cells.
In the body, hemolysis is constantly carried out in small quantities during the death of old red blood cells. Normally, it occurs only in the liver, spleen, red bone marrow. In this case, hemoglobin is “absorbed” by the cells of these organs and is absent in the circulating blood plasma. Under certain conditions of the body, hemolysis in vascular system exceeds the normal range, hemoglobin appears in the plasma of circulating blood (hemoglobinemia) and begins to be excreted in the urine (hemoglobinuria). This is observed, for example, with the bite of poisonous snakes, scorpions, multiple bee stings, with malaria, transfusion of blood that is incompatible in a group relation.
Blood reaction. The reaction of the medium is determined by the concentration of hydrogen ions. To determine the degree of displacement of the reaction of the environment, the hydrogen indicator, denoted by pH, is used. The active reaction of the blood of higher animals and humans is a value characterized by high constancy. As a rule, it does not go beyond 7.36-7.42 (weakly alkaline).
The shift of the reaction to the acid side is called acidosis, which is caused by an increase in the blood of H + ions. There is a decrease in the function of the central nervous system and with a significant acidotic state of the body, loss of consciousness may occur, and later death.
The shift in the reaction of blood to the alkaline side is called alkalosis. The occurrence of alkalosis is associated with an increase in the concentration of hydroxyl ions OH - . In this case, overexcitation of the nervous system occurs, the appearance of convulsions is noted, and later the death of the body.
Consequently, body cells are very sensitive to pH shifts. A change in the concentration of hydrogen (H +) and hydroxide (OH -) ions in one direction or another disrupts the vital activity of cells, which can lead to serious consequences.
In the body, there are always conditions for a shift in the reaction towards acidosis or alkalosis. Acid products are constantly formed in cells and tissues: lactic, phosphoric and sulfuric acids (during the oxidation of phosphorus and sulfur of protein foods). With increased consumption of plant foods, sodium, potassium, and calcium bases constantly enter the bloodstream. On the contrary, with a predominant diet of meat food in the blood, conditions are created for the accumulation of acidic compounds. However, the magnitude of the blood reaction is constant. Maintaining the constancy of the blood reaction to provide the so-called buffer systems, I also mainly activity of the lungs, kidneys and sweat glands.
Blood buffer systems include: 1) carbonate buffer system (carbonic acid - H 2 CO 3, sodium bicarbonate - NaHCO 3); 2) phosphate buffer system (monobasic - NaH 2 PО 4 and dibasic - Na 2 HPO 4 sodium phosphate); 3) hemoglobin buffer system (hemoglobin-potassium salt of hemoglobin); 4) buffer system of plasma proteins.
These buffer systems neutralize a significant part of the acids and alkalis entering the blood and thereby prevent a shift in the active reaction of the blood. The main tissue buffers are proteins and phosphates.
The activity of some organs also contributes to the maintenance of pH constancy. Thus, an excess of carbon dioxide is given through the lungs. Kidneys with acidosis secrete more acid monobasic sodium phosphate, with alkalosis - more alkaline salts (dibasic sodium phosphate and sodium bicarbonate). The sweat glands can secrete lactic acid in small amounts.
In the process of metabolism, more acidic products are formed than alkaline products, so the danger of a reaction shift towards acidosis is greater than the danger of a shift towards alkalosis. Accordingly, the buffer systems of the blood and tissues provide greater resistance to acids than to alkalis. So, to shift the reaction of blood plasma to the alkaline side, it is necessary to add 40-70 times more sodium hydroxide to it than to clean water. In order to cause a shift in the reaction of blood to the acid side, it is necessary to add 327 times more hydrochloric (hydrochloric) acid to it than to water. Alkaline salts of weak acids contained in the blood form the so-called alkaline blood reserve. However, despite the presence of buffer systems and good protection of the body from possible changes in blood pH, shifts towards acidosis or alkalosis still sometimes occur both in physiological and, especially, in pathological conditions.
Formed elements of blood
The formed elements of blood are erythrocytes(red blood cells) leukocytes(white blood cells) platelets(blood plates).
red blood cells
Erythrocytes are highly specialized blood cells. In humans and mammals, erythrocytes lack a nucleus and have a homogeneous protoplasm. Erythrocytes have the shape of a biconcave disc. Their diameter is 7-8 microns, the thickness along the periphery is 2-2.5 microns, in the center - 1-2 microns.
1 liter of men's blood contains 4.5 10 12 / l-5.5 10 12 / l 4.5-5.5 million in 1 mm 3 erythrocytes), women - 3.7 10 12 / l- 4.7 10 12 / l (3.7-4.7 million in 1 mm 3), newborns - up to 6.0 10 12 / l (up to 6 million in 1 mm 3), elderly people - 4 ,0 10 12 / l (less than 4 million in 1 mm 3).
The number of red blood cells changes under the influence of external and internal environmental factors (daily and seasonal fluctuations, muscle work, emotions, staying at high altitudes, fluid loss, etc.). An increase in the number of red blood cells in the blood is called erythrocytosis, lowering - erythropenia.
Functions of red blood cells. Respiratory the function is performed by erythrocytes due to the hemoglobin pigment, which has the ability to attach to itself and give off oxygen and carbon dioxide.
Nutritious the function of erythrocytes is to adsorb amino acids on their surface, which they transport to the cells of the body from the digestive organs.
Protective the function of erythrocytes is determined by their ability to bind toxins (harmful, poisonous substances for the body) due to the presence on the surface of erythrocytes of special substances of a protein nature - antibodies. In addition, erythrocytes take an active part in one of the most important protective reactions of the body - blood clotting.
Enzymatic The function of erythrocytes is related to the fact that they are carriers of various enzymes. In erythrocytes found: true cholinesterase- an enzyme that breaks down acetylcholine carbonic anhydrase- an enzyme that, depending on the conditions, promotes the formation or breakdown of carbonic acid in the blood of tissue capillaries methemoglobin reductase- an enzyme that maintains hemoglobin in a reduced state.
Regulation of blood pH is carried out by erythrocytes through hemoglobin. Hemoglobin buffer is one of the most powerful buffers, it provides 70-75% of the total buffer capacity of the blood. The buffer properties of hemoglobin are due to the fact that he and his compounds have the properties of weak acids.
Hemoglobin
Hemoglobin is a respiratory pigment in the blood of humans and vertebrates, it plays an important role in the body as an oxygen carrier and takes part in the transport of carbon dioxide.
The blood contains a significant amount of hemoglobin: 1 10 -1 kg (100 g) of blood contains up to 1.67 10 -2 -1.74 10 -2 kg (16.67-17.4 g) of hemoglobin. In men, the blood contains an average of 140-160 g / l (14-16 g%) of hemoglobin, in women - 120-140 g / l (12-14 g%). The total amount of hemoglobin in the blood is approximately 7·10 -1 kg (700 g); 1 10 -3 kg (1 g) of hemoglobin binds 1.345 10 -6 m 3 (1.345 ml) of oxygen.
Hemoglobin is a complex chemical compound consisting of 600 amino acids, its molecular weight is 66000±2000.
Hemoglobin is made up of the protein globin and four heme molecules. A heme molecule containing an iron atom has the ability to attach or donate an oxygen molecule. In this case, the valence of iron, to which oxygen is attached, does not change, i.e., iron remains divalent (F ++). Heme is the active, or so-called prosthetic, group, and globin is the protein carrier of heme.
Recently, it has been established that blood hemoglobin is heterogeneous. Three types of hemoglobin were found in human blood, designated as HbP (primitive, or primary; found in the blood of 7-12-week-old human embryos), HbF (fetal, from Latin fetus - fetus; appears in the blood of the fetus at the 9th week of intrauterine development), HbA (from lat. adultus - adult; found in the blood of the fetus simultaneously with fetal hemoglobin). By the end of the 1st year of life, fetal hemoglobin is completely replaced by adult hemoglobin.
Different types of hemoglobin differ in amino acid composition, alkali resistance and oxygen affinity (the ability to bind oxygen). Thus, HbF is more resistant to alkalis than HbA. It can be saturated with oxygen by 60%, although under the same conditions the mother's hemoglobin is only 30% saturated.
myoglobin. Muscle hemoglobin is found in skeletal and cardiac muscles, or myoglobin. Its prosthetic group - heme - is identical to the heme of the blood hemoglobin molecule, and the protein part - globin - has a lower molecular weight than the hemoglobin protein. Human myoglobin binds up to 14% of the total amount of oxygen in the body. It plays an important role in supplying oxygen to working muscles.
Hemoglobin is synthesized in the cells of the red bone marrow. For the normal synthesis of hemoglobin, a sufficient supply of iron is necessary. The destruction of the hemoglobin molecule is carried out mainly in the cells of the mononuclear phagocytic system (reticuloendothelial system), which includes the liver, spleen, bone marrow, monocytes. In some blood diseases, hemoglobins have been found that differ in chemical structure and properties from the hemoglobin of healthy people. These types of hemoglobin are called abnormal hemoglobins.
Functions of hemoglobin. Hemoglobin performs its functions only when it is present in red blood cells. If, for some reason, hemoglobin appears in the plasma (hemoglobinemia), then it is unable to perform its functions, as it is quickly captured by the cells of the mononuclear phagocytic system and destroyed, and part of it is excreted through the renal filter (hemoglobinuria). The appearance of a large amount of hemoglobin in the plasma increases the viscosity of the blood, increases the magnitude of the oncotic pressure, which leads to a violation of the movement of blood and the formation of tissue fluid.
Hemoglobin performs the following main functions. Respiratory The function of hemoglobin is carried out due to the transfer of oxygen from the lungs to the tissues and carbon dioxide from the cells to the respiratory organs. Active response regulation blood or acid-base state is due to the fact that hemoglobin has buffer properties.
Hemoglobin compounds. Hemoglobin, which has attached oxygen to itself, turns into oxyhemoglobin (HbO 2). Oxygen with the heme of hemoglobin forms an unstable compound in which iron remains divalent (covalent bond). Hemoglobin that has given up oxygen is called restored or reduced, hemoglobin (Hb). Hemoglobin attached to carbon dioxide is called carbohemoglobin(HbCO 2). Carbon dioxide with the protein component of hemoglobin also forms an easily decomposing compound.
Hemoglobin can enter into combination not only with oxygen and carbon dioxide, but also with other gases, for example, with carbon monoxide(CO). Hemoglobin combined with carbon monoxide is called carboxyhemoglobin(HbCO). Carbon monoxide, like oxygen, combines with the heme of hemoglobin. Carboxyhemoglobin is a strong compound, it releases carbon monoxide very slowly. As a result, carbon monoxide poisoning is very life-threatening.
For some pathological conditions, for example, in case of poisoning with phenacetin, amyl and propyl nitrites, etc., a strong connection of hemoglobin with oxygen appears in the blood - methemoglobin, in which an oxygen molecule attaches to the iron, oxidizes it and the iron becomes trivalent (MetHb). In cases of accumulation of large amounts of methemoglobin in the blood, the transport of oxygen to the tissues becomes impossible and the person dies.
Leukocytes
Leukocytes, or white blood cells, are colorless cells containing a nucleus and protoplasm. Their size is 8-20 microns.
In the blood of healthy people at rest, the number of leukocytes ranges from 6.0 10 9 / l - 8.0 10 9 / l (6000-8000 in 1 mm 3). Numerous recent studies indicate a slightly larger range of these fluctuations 4·10 9 /l - 10·10 9 /l (4000-10000 in 1 mm 3).
An increase in the number of white blood cells in the blood is called leukocytosis, decrease - leukopenia.
Leukocytes are divided into two groups: granular leukocytes, or granulocytes, and non-granular, or agranulocytes.
Granular leukocytes differ from non-granular ones in that their protoplasm has inclusions in the form of grains that can be stained with various dyes. Granulocytes include neutrophils, eosinophils, and basophils. Neutrophils according to the degree of maturity are divided into myelocytes, metamyelocytes (young neutrophils), stab and segmented. The bulk of the circulating blood is segmented neutrophils (51-67%). Stab can contain no more than 3-6%. Myelocytes and metamyelocytes (young) do not occur in the blood of healthy people.
Agranulocytes do not have specific granularity in their protoplasm. These include lymphocytes and monocytes. It has now been established that lymphocytes are morphologically and functionally heterogeneous. There are T-lymphocytes (thymus-dependent), maturing in the thymus gland, and B-lymphocytes, which are formed, apparently, in Peyer's patches (clusters of lymphoid tissue in the intestine). Monocytes are probably formed in the bone marrow and lymph nodes. There are certain relationships between individual types of leukocytes. The percentage ratio between individual types of leukocytes is called leukocyte formula (Table 1).
In a number of diseases, the nature of the leukocyte formula changes. For example, in acute inflammatory processes (acute bronchitis, inflammation of the lungs) increases the number of neutrophilic leukocytes (neutrophilia). For allergic conditions ( bronchial asthma, hay fever) mainly increases the content of eosinophils (eosinophilia). Eosinophilia is also observed in helminthic invasions. For sluggish current chronic diseases(rheumatism, tuberculosis) is characterized by an increase in the number of lymphocytes (lymphocytosis). Thus, the calculation of the leukocyte formula has an important diagnostic value.
Properties of leukocytes. Leukocytes have a number of important physiological properties: amoeboid mobility, diapedesis, phagocytosis. Amoeba mobility- this is the ability of leukocytes to actively move due to the formation of protoplasmic outgrowths - pseudopodia (pseudopodia). Diapedesis should be understood as the property of leukocytes to penetrate through the capillary wall. In addition, leukocytes can absorb and digest foreign bodies and microorganisms. This phenomenon, studied and described by I. I. Mechnikov, was called phagocytosis.
Phagocytosis proceeds in four phases: approach, adhesion (attraction), immersion, and intracellular digestion (phagocytosis proper) (Fig. 3).
Leukocytes that absorb and digest microorganisms are called phagocytes(from Greek phagein - to devour). Leukocytes absorb not only bacteria that have entered the body, but also dying cells of the body itself. The movement (migration) of leukocytes to the focus of inflammation is due to a number of factors: an increase in temperature in the focus of inflammation, a shift in pH to the acid side, the existence of chemotaxis(the movement of leukocytes towards a chemical stimulus is positive chemotaxis, and from it is negative chemotaxis). Chemotaxis is provided by the waste products of microorganisms and substances formed as a result of tissue breakdown.
Neutrophilic leukocytes, monocytes and eosinophils are phagocyte cells, lymphocytes also have phagocytic ability.
Functions of leukocytes. One of the most important functions performed by leukocytes is protective. Leukocytes are able to produce special substances - leukins, which cause the death of microorganisms that have entered the human body. Some leukocytes (basophils, eosinophils) form antitoxins- substances that neutralize the waste products of bacteria, and thus have a detoxifying property. Leukocytes are capable of producing antibodies- substances that neutralize the action of toxic metabolic products of microorganisms that have entered the human body. In this case, the production of antibodies is carried out mainly by B-lymphocytes after their interaction with T-lymphocytes. T-lymphocytes are involved in cellular immunity, providing a transplant rejection reaction (transplanted organ or tissue). Antibodies can long time be stored in the body as an integral part of the blood, so re-infection of a person becomes impossible. This state of immunity to diseases is called immunity. Therefore, playing a significant role in the development of immunity, leukocytes (lymphocytes) thereby perform a protective function. Finally, leukocytes (basophils, eosinophils) are involved in blood coagulation and fibrinolysis.
Leukocytes stimulate regenerative (restorative) processes in the body, accelerate wound healing. This is due to the ability of leukocytes to participate in the formation trephons.
Leukocytes (monocytes) take an active part in the processes of destruction of dying cells and body tissues due to phagocytosis.
Leukocytes carry out enzymatic function. They contain various enzymes (proteolytic - splitting proteins, lipolytic - fats, amylolytic - carbohydrates) necessary for the process of intracellular digestion.
Immunity. Immunity is a way of protecting the body from living bodies and substances that have genetically alien characteristics. Complex reactions of immunity are carried out due to the activity of a special immune system organism - specialized cells, tissues and organs. The immune system should be understood as the totality of all lymphoid organs ( thymus, spleen, The lymph nodes) and accumulations of lymphoid cells. The main element of the lymphoid system is the lymphocyte.
There are two types of immunity: humoral and cellular. Humoral immunity is carried out mainly by B-lymphocytes. B-lymphocytes, as a result of complex interactions with T-lymphocytes and monocytes, turn into plasmocytes- cells that produce antibodies. The task of humoral immunity is to free the body from foreign proteins (bacteria, viruses, etc.) that enter it from environment. Cellular immunity(the reaction of transplanted tissue rejection, the destruction of genetically degenerated cells of one's own body) is provided mainly by T-lymphocytes. In reactions cellular immunity macrophages (monocytes) are also involved.
The functional state of the body's immune system is regulated by complex nervous and humoral mechanisms.
platelets
Platelets, or platelets, are oval or rounded formations with a diameter of 2-5 microns. Human and mammalian platelets do not have nuclei. The content of platelets in the blood ranges from 180 10 9 / l to 320 10 9 / l (from 180,000 to 320,000 1 mm 3). An increase in the number of platelets in the blood is called thrombocytosis, a decrease is called thrombocytopenia.
Properties of platelets. Platelets, like leukocytes, are capable of phagocytosis and movement due to the formation of pseudopodia (pseudopodia). The physiological properties of platelets also include adhesiveness, aggregation and agglutination. Adhesion refers to the ability of platelets to adhere to a foreign surface. Aggregation is the property of platelets to stick to each other under the influence of various reasons, including factors that contribute to blood clotting. Agglutination of platelets (gluing them together) is carried out by antiplatelet antibodies. Viscous metamorphosis of platelets - a complex of physiological and morphological changes up to cell breakdown, along with adhesion, aggregation and agglutination, plays an important role in the hemostatic function of the body (i.e., in stopping bleeding). Speaking about the properties of platelets, one should emphasize their "readiness" for destruction, as well as the ability to absorb and release certain substances, in particular serotonin. All the considered features of platelets determine their participation in stopping bleeding.
Platelet Functions. 1) Take an active part in the process blood clotting and fibrinolysis(dissolution blood clot). A large number of factors (14) were found in the plates, which determine their participation in stopping bleeding (hemostasis).
2) They perform a protective function due to agglutination of bacteria and phagocytosis.
3) They are able to produce some enzymes (amylolytic, proteolytic, etc.), which are necessary not only for the normal functioning of the plates, but also to stop bleeding.
4) They affect the state of histohematic barriers, changing the permeability of the capillary wall due to the release of serotonin and a special protein - protein S into the bloodstream.
In 1898, a scientist named Bunge, hypothesized that life originated in the sea. He argued that animals living today inherited the inorganic composition of blood from their ancestors. Scientists also deduced the formula for sea water from the Paleozoic era. You know what's amazing? The composition of this ancient water is completely identical to the mineral composition of our blood. What happens. Are the waters of the ancient sea flowing in us? So maybe that's why we are so drawn to the sea.
Millions of years ago, the waters of the ocean became the cradle of life on Earth. In those distant times, the first single-celled living organisms lived in the water expanses of the earth. They drew from the water the nutrients and oxygen necessary for life. The ocean provided them with a constant temperature. As time went. Organisms became multicellular and captivated the sea inside themselves, so as not to lose the possibility of water, also to help the now grown organism, to live as comfortably as it was with unicellular ancestors. As a result, in the process of evolution, we came to the appearance of blood, the composition of which is surprisingly similar to the composition of sea water.
The main component of the liquid part of the blood - plasma - is water (90-92%), practically the only solvent in which all chemical transformations in the body occur. Let's compare the composition of sea water and blood plasma. AT sea water salt concentration is higher. The content of calcium and sodium is the same. Magnesium and chlorine are more in sea water, and potassium is more in blood serum. The salt composition of the blood is constant, it is maintained and controlled by special buffer systems. Surprisingly, the salt composition of the oceans is also constant. Fluctuations in the composition of individual salts do not exceed 1%. During the Second World War, A. Babkin and V. Sosnovsky proposed a preparation of sea water to replenish the blood loss of the wounded. This drug went down in history under the name of Babsky's AM-4 solution.
What is the composition of sea water and how does it affect us?
Sea salt is common sodium chloride. In percentage terms, it is contained in sea water as much as in the body. healthy person. Therefore, swimming in the sea helps to maintain a normal acid-base balance in our body and has a beneficial effect on the skin.
Calcium drives away depression, promotes good sleep and guarantees the absence of convulsions, takes part in blood clotting, plays an important role in wound healing, preventing infections and strengthens connective tissues.
Magnesium protects against allergies, nervousness, relieves swelling, is involved in cell metabolism and muscle relaxation.
Bromine calms the nervous system.
Sulfur has a beneficial effect on the skin and fights fungal diseases.
Iodine is essential for thyroid gland, affects intellectual abilities, hormonal metabolism, lowers cholesterol levels in the blood, rejuvenates skin cells.
Potassium is involved in the regulation of nutrition and cell cleansing.
Chlorine is involved in education gastric juice and blood plasma.
Manganese is involved in the formation of bone tissue and strengthens the immune system.
Zinc is involved in the formation of immunity, maintaining the function of the sex glands, and prevents the growth of tumors.
Iron is involved in the transport of oxygen and in the formation of red blood cells.
Selenium prevents cancer.
Copper prevents the development of anemia.
Silicon gives elasticity to blood vessels and strengthens tissues.
Blood in our body harmonizes all vital processes, the work of organs and tissues, linking the body into a single whole. The progenitor of blood - the world ocean - performs the same functions in an organism called planet Earth ...
Blood and ocean. They protect, nourish, warm, cleanse the body and the planet, organs and continents, billions of cells and billions of living beings. The life of the cells of our body and the life of all living beings on planet Earth is impossible without water and blood.
According to V. A. Andreev and Abdergalden, 1000 weight parts of fresh blood of various farm animals contain the following amount of different substances:
as well as small amounts of potassium, iron oxide, calcium, phosphorus, magnesium, chlorine and inorganic phosphorus.
The bulk of solids in the blood are proteins and primarily hemoglobin. The latter belongs to the protein substances of the chromeoprotein group; it is able to crystallize, and its crystals in different animals are sharply different in shape. Hemoglobin is a very unstable substance, which makes it difficult to determine it. chemical composition. Oxyhemoglobin (according to Hoppe) has the following composition: C - 53.85%; H - 7.32%; N- 16.17%; O - 21.84%; S - 0.39%; Fe - 0.43%. Hemoglobin and oxyhemoglobin are found only in red blood cells.
Serum albumin and globulin predominate among other blood proteins. Both of these proteins (included in the group of simple proteins - proteins) belong to the number of coagulated proteins, as they coagulate when heated. They easily dissolve in weak solutions of acids, alkalis and salts, falling out of these solutions in the form of a precipitate with further addition of acid. Albumin is also readily soluble in water; globulin is insoluble in water.
Albumin is characterized by its sulfur content and the absence of glycocol. The composition of horse serum albumin, according to Abdergalden, is as follows: C - 53.08%; H - 6.96%; N - 15.93%; S - 1.9%; O - 22.99%. Its amino acid composition is as follows:
In its pure form, blood albumin is a solid crystalline or amorphous substance of a whitish or yellowish color. According to Hammarsten, the blood of various farm animals contains albumin:
Globulin has the following elemental composition (according to Abdergalden): C - 52.71%; H - 7.01%; N - 15.85%; S - 1.11%; O - 23.32%. The amino acid composition of globulin is as follows:
From the above data, it can be seen that the chemical composition of albumins and globulins is very close to each other.
In blood various kinds farm animals contain the following amount of globulins:
Albumin and globulin are characteristic mainly of blood plasma.
In the blood plasma there is a special protein substance - fibrinogen. Its role in blood coagulation is discussed below. The amount of fibrinogen in the blood is usually 0.4-0.5%.
Blood sugar is represented mainly by glucose.
Of the lipoids in the blood, both neutral fats and cholesterols and lecithins are constantly present. Their number varies depending on the nature of the food of the animal.
Blood minerals are approximately 75% chloride and 25% carbonates and phosphates (the latter are very few).
In 1000 parts of the plasma of defibrinated blood (the so-called "serum") of different animals contains the following amount of different substances:
Thus, there is no hemoglobin in the blood plasma, and consequently, iron oxide, but almost all the amount of sugars, fats and fatty acids in the blood is concentrated in the plasma. Plasma is characterized by the presence of fibrinogen and a large amount of albumin and globulins. Of the mineral substances, Na salts predominate, especially NaCl.
Chemical composition of the separated mass of blood cells different types farm animals such (in ppm):
The bulk of the blood cells are erythrocytes (about 99.9%). Red blood cells contain about 60% water and about 40% solids. 75-85% of this dry matter is hemoglobin, and the remaining 15-25% is various proteins (65%) and lipoids (35%). Lipoids are found predominantly in the membrane of erythrocytes.
The protoplasm of white blood cells consists mainly of cytoproteins, and their nuclei of nucleoproteins containing phosphorus.
The reaction of blood when determining it with litmus is slightly alkaline; The pH of the blood of various animal species ranges from 7.24 to 7.97. These figures show that the reaction of the blood is almost neutral and very slightly shifted towards alkalinity.
The freezing point of fresh blood is 0.56°. The osmotic pressure is approximately 7 atm (almost the same in the blood of different animals).
The specific gravity of blood Y = 1.055, erythrocytes Y = 1.08, plasma Y = 1.027-1.034. The greater specific gravity of erythrocytes allows them to be separated from plasma by separation.
The viscosity of blood, determined by studying the speed of its flow through a capillary tube, compared with water is approximately 5 ° Oe. It varies depending on the content of blood cells and the percentage of dry residue.
The viscosity of the defibrated blood of cattle is 2.5° Oe; the viscosity of her serum is 1.75° Oe; the viscosity of the formed elements is 80.0 ° Oe (according to V. A. Andreev).
It can be seen from the above that the chemical composition and physical properties blood of different types of farm animals have some very significant differences.
The blood of pigs is characterized by a high content of formed elements (42% of the total mass of blood), which leads to a high yield of dry residue during evaporation (21%). The content of hemoglobin in pig blood is very high (14%). On the contrary, there are fewer other proteins than in the blood of other farm animals. The cholesterol content is insignificant, although the amount of neutral fats is very high. Of the minerals in the blood of pigs, there are relatively many potassium salts, but few sodium salts. Blood plasma is almost colorless, as it is devoid of pigments.
The blood of cattle contains only 19% of dry matter; a higher water content causes a smaller number of formed elements (35%). Accordingly, hemoglobin in the blood of cattle is less (10%) than in the blood of pigs (14%). The amount of other proteins is 11/2 times more. Fat in the blood of cattle is very small, but the amount of cholesterol is relatively large. Of the salts, sodium salts sharply predominate.
Sheep blood is similar in composition to the blood of cattle, but has an even smaller amount of formed elements (about 30%), solids (18%) and hemoglobin (9%). The amount of fat is relatively high. The composition of mineral substances is almost the same as in the blood of cattle.
The blood of horses contains 40% formed elements and 20% solids. The amount of hemoglobin is relatively high (12.5%). Cholesterol and neutral fats are low.
Protecting the body from pathogenic microbes
If a person weighs 65 kg, he has 5.2 kg of blood (7-8%); Of 5 liters of blood, about 2.5 liters are water.
The composition of plasma (it accounts for 55%) includes minerals (salts of sodium, calcium, and many others) and organic (proteins, glucose, and others). Plasma takes part in the transport of substances and blood coagulation.
Figure 1.5.7. Dynamic balance of blood coagulation and fibrinolysis systems:
1 - wall of a blood vessel; 2 - damage to the vessel wall; 3 - platelets; 4 - adhesion and aggregation of platelets; 5 - thrombus; 6 - coagulation system factors
As can be seen in this figure, blood coagulation is based on the conversion of soluble plasma protein fibrinogen into dense protein fibrin . Among the agents of the process are calcium ions and prothrombin. If a small amount of sodium oxalate or citrate (sodium citrate) is added to fresh blood, then clotting will not occur, since these compounds bind calcium ions so strongly. This is used when storing donated blood. Another substance that is required for the normal course of the blood coagulation process is the previously mentioned prothrombin. This plasma protein is produced in the liver, and vitamin K is necessary for its formation. The components listed above (fibrinogen, calcium ions and prothrombin) are always present in the blood plasma, but under normal conditions, the blood does not coagulate.
The fact is that the process cannot start without one more component - thromboplastin - an enzymatic protein contained in platelets and in the cells of all tissues of the body. If you cut your finger, thromboplastin is released from the damaged cells. Thromboplastin is also secreted from platelets that are destroyed during bleeding. When interacting in the presence of calcium ions, thromboplastin with prothrombin, the latter is cleaved and forms an enzyme thrombin , which converts soluble protein fibrinogen into insoluble fibrin . Platelets play an important role in the mechanism of stopping bleeding. As long as the vessels are not damaged, platelets do not stick to the walls of the vessels, but if their integrity is violated or pathological roughness (for example, an atherosclerotic plaque) appears, they settle on the damaged surface, stick together with each other and release substances that stimulate blood coagulation. This is how a blood clot is formed, which, when growing, turns into a blood clot.
The process of thrombus formation is a complex chain of interactions of various factors and consists of several stages. At the first stage, the formation of tomboplastin occurs. A number of plasma and platelet coagulation factors take part in this phase. In the second phase, thromboplastin in combination with coagulation factors VII and X and in the presence of calcium ions convert the inactive prothrombin protein into the active thrombin enzyme. In the third phase, the soluble protein fibrinogen (under the action of thrombin) is converted into insoluble fibrin. Fibrin threads, woven into a dense network, with captured platelets form a clot - a thrombus - covering the defect of the blood vessel.
The liquid state of the blood under normal conditions maintains an anticoagulant - antithrombin . It is produced in the liver and its role is to neutralize small amounts of thrombin that appear in the blood. If, nevertheless, the formation of a blood clot has occurred, then the process of thrombolysis or fibrinolysis begins, as a result of which the thrombus gradually dissolves and the patency of the vessel is restored. If you look again at figure 1.5.7, or rather, on its right side, you can see that the destruction of fibrin occurs under the action of the enzyme plasmin . This enzyme is formed from its precursor plasminogen under the influence of certain factors called plasminogen activators .
Blood is a biological fluid that provides organs and tissues with nutrients and oxygen. Together with lymph, it forms a system of fluids circulating in the body. It performs a number of vital functions: nutritional, excretory, protective, respiratory, mechanical, regulatory, thermoregulatory.
The composition of human blood changes significantly with age. It should be said that children have a very intensive metabolism, therefore, in their body it is much more per 1 kg of body weight compared to adults. On average, an adult has about five to six liters of this biological fluid.
The composition of the blood includes plasma (the liquid part) and leukocytes, platelets). Its color depends on the concentration of red blood cells. Plasma devoid of protein (fibrinogen) is called blood serum. This biological fluid has a slightly alkaline reaction.
Biochemical composition of blood - buffer systems. The main blood buffers are bicarbonate (7% of the total mass), phosphate (1%), protein (10%), hemoglobin and oxyhemoglobin (up to 81%), as well as acid (about 1%) systems. In plasma, hydrocarbonate, phosphate, proteinaceous and acidic prevail, in erythrocytes - hydrocarbonate, phosphate, in hemoglobin - oxyhemoglobinic and acidic. The composition of the acid buffer system is represented by organic acids (acetate, lactate, pyruvic, etc.) and their salts with strong bases. Highest value have bicarbonate and hemoglobin buffer systems.
The chemical composition is characterized by the constancy of the chemical composition. Plasma makes up 55-60% of the total blood volume and is 90% water. are organic (9%) and mineral (1%) substances. The main organic substances are proteins, most of which are synthesized in the liver.
Protein composition blood. The total content of proteins in the blood of mammals ranges from 6 to 8%. About a hundred protein components of plasma are known. Conventionally, they can be divided into three fractions: albumins, globulins and fibrinogen. Plasma proteins that remain after the removal of fibrinagen are called serum proteins.
Albumins take part in the transport of many nutrients and (carbohydrates, fatty acids, vitamins, inorganic ions, bilirubin). Involved in regulation Serum globulins are divided into three fractions alpha, beta and gamma globulins. Globulins transport fatty acids, steroid hormones, are immune bodies.
Carbohydrate composition of the blood. Plasma contains monoses (glucose, fructose), glycogen, glucosamine, monose phosphates and other products of intermediate carbohydrate metabolism. The main part of carbohydrates is represented by glucose. Glucose and other monoses in the blood plasma are in free and protein-bound states. The content of bound glucose reaches 40-50% of the total carbohydrate content. Among the products of the intermediate metabolism of carbohydrates, lactic acid is isolated, the content of which increases sharply after heavy physical activity.
Glucose concentration can change under many pathological conditions. The phenomenon of hyperglycemia is characteristic of diabetes, hyperthyroidism, shock, anesthesia, fever.
The lipid composition of the blood. Plasma contains up to 0.7% or more lipids. Lipids are found in free and protein-bound states. Plasma lipid concentration changes with pathology. So, with tuberculosis, it can reach 3-10%.
The gas composition of the blood. This bioliquid contains oxygen (oxygen), carbon dioxide and nitrogen in free and bound states. So, for example, about 99.5-99.7% of oxygen is associated with hemoglobin, and 03-0.5% is in a free state.
