Plasma is the liquid part of blood. It can be seen on the wound if its surface is large enough for this. When the red cells settle, a translucent fluid remains. Plasma should not be confused with blood serum. Serum is the liquid part of the blood that does not contain fibrinogen (clotting protein). Plasma, together with other liquids, makes up the internal environment of the body in which many processes take place. It performs a number of important functions.

Plasma makes up more than half of the body's total blood and is the liquid part of it. Human blood includes various bodies and cells (,), as well as a liquid medium in which all these elements are located and transported.

The composition of human blood plasma includes water, proteins, other organic and inorganic compounds, salts, called plasma solids. The majority is water (more than 90%). There is a practice of collecting donor plasma and transfusing it if necessary.

Externally, plasma looks like a transparent, slightly thick, sometimes cloudy or yellowish liquid. Most of the dry residue consists of proteins.

All functions of blood plasma, as a rule, are determined precisely by the action of proteins:

• Transport of substances. Plasma serves as a transport fluid for copper, proteins, various drugs, lipids, and fatty acids. Thanks to plasma various substances and blood elements can freely reach tissues and organs. Each protein is responsible for the transport of a particular substance.
• Maintenance osmotic pressure blood. Plasma maintains normal blood volume as well as normal fluid volume in tissues and cells. For this reason, when the protein composition is disturbed (especially), edema is often observed due to impaired fluid outflow.
• Protection of the body. The role of plasma in maintaining normal operation immune system very big. Plasma contains elements that are able to recognize, bind and destroy foreign cells. They protect tissues and are activated when inflammation occurs.
• Maintaining the process. This is the most important function of plasma. Many proteins in plasma are involved in the clotting process and prevent extensive blood loss. In addition, plasma is also responsible for the regulation of this process, that is, for the anticoagulant ability of the blood, the dissolution of blood clots and their prevention.
• Maintaining acid-base balance. Plasma maintains a normal level of acid-base composition of the blood.

Protein organic substances in plasma

Protein substances are the main part of blood plasma, which perform very important functions

Proteins make up the majority of plasma solids and are responsible for the vast majority of its functions. Plasma contains a huge number of proteins (more than 500 varieties).

It is proteins that participate in the process, bind and transport substances to organs and tissues, and help maintain acid-base balance blood is normal, and also support the functioning of the immune system, destroying hostile cells.

Blood plasma proteins:

• Albumin. The largest group of proteins, which makes up more than half of the total dry residue of blood plasma. They are dissolved in plasma and tend to coagulate when heated. Albumin, which is contained in plasma, is also called serum. It is produced by the liver and performs a transport and nutritional function. The albumin molecule is small, but one such molecule can bind up to 50 molecules. Normal quantity albumin in plasma 35-50 g/l. Reduced levels of this protein may indicate disease.
• Globulins. Globulins have larger molecules than albumins and are less soluble in liquids. Globulins are also produced by the liver and perform protective, transport function, regulate . Globulins are usually divided into several varieties, each of which is responsible for transporting a particular substance. For example, a-globulin is responsible for the transfer of vitamins and microelements. Other types of globulin transport iron and are also responsible for activating immune processes.
• Fibrinogen. This protein is responsible for blood clotting. Under the influence of thrombin, fibrinogen becomes insoluble and turns into fibrin, which plays important role in the formation and dissolution of blood clots. The fibrinogen norm is 2-4 g/l. During this time, the level of this protein in the blood plasma may increase due to physiological reasons. Blood plasma without fibrinogen is called blood serum. Increased level fibrinogen can lead to various cardiovascular diseases.

In addition to proteins, plasma contains large number other organic compounds, as well as mineral and inorganic substances, salts, metabolic products. To non-protein organic matter nitrogen and its varieties can be classified as mineral and inorganic substances, potassium, calcium, phosphorus, sodium, etc.

The total amount of inorganic substances in plasma, as a rule, is less than 1% of the total plasma volume:

• Nitrogen and nitrogen-containing substances in blood plasma. Plasma contains nitrogen in the form of ammonia, urea nitrogen, uric acid. As a rule, human blood plasma contains very little nitrogen and nitrogenous compounds. If their number increases, we can talk about pathological condition body. Because more(more than 50%) of the total nitrogen in the body is contained in, but when the level of nitrogen in the plasma increases, a dysfunction is suspected.
• . Glucose is called simple glucose, which is an irreplaceable source of energy and is released during the breakdown of carbohydrates. The body uses glucose thanks to a hormone called insulin. It breaks down glucose and regulates its transport to various cells. If suspected, the level of glucose must be determined, both in the blood and in the plasma separately, while in whole blood the glucose concentration will be lower than in plasma.
• Lipids. Blood plasma contains various lipids: phospholipids, triglycerides, various fatty acids. is part of cell membranes and is a kind of cellular building material. However, when its content in the blood becomes too high, it begins to settle on the walls blood vessels, forming cholesterol plaques.
• Sodium. Sodium, as a rule, is practically not contained in the cells of the body, but is the most important regulator of extracellular fluid circulation. Plasma sodium concentration increases with active sweating and fluid loss.

Disorders of the protein composition of blood plasma

Proteins contained in plasma perform many important functions, therefore, if the content of one or more proteins is disrupted, malfunctions begin to occur in the body and metabolism is disrupted.

The reasons for such violations are varied. Most proteins and others nutrients enter the body with food, so when poor nutrition, excess carbohydrates and lack of protein may cause disturbances in the protein composition of blood plasma.Excess protein is also not beneficial and leads to various violations. Only the right thing balanced diet will help maintain plasma protein levels at the desired level.

Protein disorders are not always related to diet. Sometimes the composition of amino acids in proteins is disrupted or the breakdown of proteins in the body is disrupted due to some pathological conditions.

Increased protein content is observed in diseases digestive system when the absorption of amino acids in the intestines is impaired.Disorders of protein metabolism are the cause of such a well-known disease as gout, as a result of which large amounts of uric acid accumulate in the body. Gout is often caused by insufficiently varied food, an abundance of meat dishes, alcohol abuse, and lack of physical activity.

Useful video - Functions and composition of blood:

With a lack of protein, conditions such as low body weight, edema, chronic fatigue, developmental delay in children, frequent colds due to decreased immunity. it will show reduced content albumin in blood serum and minerals. Severe and unbalanced protein starvation can be dangerous and fatal.At increased content protein in the plasma there is a dysfunction, lack of appetite and even aversion to food.

Diseases associated with blood plasma

Not all blood diseases affect plasma; more often they are associated with blood cells and formed elements.

Diseases associated with blood plasma are considered especially dangerous, since plasma is a carrier of the same shaped elements and nutrients throughout the body:

• Sepsis. Sepsis occurs when an infection enters the bloodstream. The blood spreads the infection throughout the body, causing serious condition. Most often, sepsis is caused by bacteria carried in the plasma throughout the body. The infection can enter the blood in various ways: through the skin, mucous membranes, orally, as well as during surgical and diagnostic procedures.
• Hemophilia. This serious illness associated with the violation. With hemophilia, the risk of death of the patient from blood loss or cerebral hemorrhage increases significantly. Any injury, even a minor one, can be dangerous. In this case, a congenital deficiency in the blood plasma of proteins responsible for coagulation is often observed.
• Von Willenbrand's disease. This disease is similar to hemophilia in the occurrence of periodic hemorrhages and bleeding. The cause of the disease is also a blood plasma protein, which is responsible for clotting and is produced in insufficient quantities. This disease is also called atrombopenic purpura. The patient often experiences bleeding gums, bleeding from the nose, mouth, and internal bleeding.
• Deep venous thrombosis. A disease in which blood clots form in the deep veins (most often) is not fatal, but it causes a lot of trouble and requires serious treatment. In some cases it is recommended surgery to restore venous patency.

All blood diseases require medical supervision. They are not treated folk remedies and can be very life-threatening.

Most people do not know what plasma is – why and what it is needed for. In fact, this is the liquid part of the blood of a certain concentration, which contains extremely important formed elements. It is a liquid that can be either transparent or have a slightly yellowish tint - this is approximately sixty percent of the total blood volume. Blood plasma may also be cloudy, which depends on nutrition and a number of other factors.

Plasma is not only found in the blood, it is also present in the tissues of the body and even enters the nephron tubule. The electrolyte composition of plasma is a set of elements such as lithium, insulin, salt, estrogens, and various vitamins. The concentration of all these elements is different for everyone. This substance performs a rather important function; it helps to thin the blood so that it can freely deliver useful substances to all cells of the body. Some people underestimate and do not understand the importance of this substance, but it contains fibrinogen, which is distinguished by the fact that it promotes rapid blood clotting.

In blood plasma, 93% is water, the rest is proteins, lipids, minerals and carbohydrates. The electrolyte composition of blood plasma is quite diverse, there is lithium, vitamins, insulin and other elements, which is why it is so valuable. In medicine, not only plasma plays a special role, but also plasma, which is obtained from fibrinogen. With the help of serum, people with serious types of diseases are treated quite successfully. Blood plasma, part of which is platelets, is used by doctors to heal tissue in the body.

It is worth noting that throughout human life, the composition of a substance can change, moreover, this happens more than once and can be repeated over time. short terms. Blood plasma changes under the influence of both external factors, and internal, a special influence on this process influences the food a person eats.

There are other factors that influence the composition of plasma, for example, strong physical activity or stressful situations.

The protein elements contained in plasma perform several important functions that have a direct impact on health:

• They take an important part in a process such as coagulation. If the blood does not contain enough protein elements, it will not clot. This is how fibrinogen differs from other proteins.
• Their functionality is also important in such a process as the movement of useful microelements and substances throughout the body.
• An acceptable concentration of a person indicates that his immunity is working as expected.
• These protein elements are also responsible for the balance of water in the blood and maintain the required concentration.

When talking about plasma, which consists mostly of water, we must not forget the important functions it performs. It is also important that absolutely every function plays a huge role in human life; we should not forget that blood bears a great responsibility, since it is responsible for transporting all metabolic products and useful substances throughout the body, which include insulin, lithium and various trace elements.

It is worth talking separately about the colorless liquid that is formed from blood plasma - it is called lymph, since many do not know what it is needed for and what its significance is. In fact, its importance for the body is invaluable, since it is it that helps cleanse it of harmful substances– this is what distinguishes it from other elements. This colorless liquid, formed from blood plasma, is a real orderly for our body - its volume is approximately two liters. Of course, it does not contain lithium, insulin and other trace elements, but it brings no less benefits to the body than plasma.

What is dry plasma?

The occurrence of any malfunction or disorder in our body leads to the fact that, in the presence of these factors, it requires special treatment and blood transfusion. Both plasma after the fraction and a certain part of the blood, with the help of which the process occurs, may be required. full recovery lost fluid.

Most often, the occurrence of such situations is associated with vascular insufficiency which occurs in the following cases:

• Severe blood loss.
• A state of shock that occurs after receiving a severe burn.
• Shock that occurs after injuries with tissue ruptures.

In this case, dry plasma acts as a substitute. Before introducing it into the human body, dry plasma is first dissolved in water. Only doctors know the exact concentration, who carefully monitor it before administering it intravenously to a person. Despite the fact that dry plasma, once it enters the body, is capable of restoring lost blood volumes, there is a risk that after its administration a person will develop hepatitis.

To prevent the patient from becoming infected with the hepatitis virus after the procedure, specialists develop and compose various techniques, the use of which significantly increases the chances of successful treatment. For example, if it is stored at room temperature or if it has been heat sterilized to preserve substances such as lithium or insulin, then the chances of contracting hepatitis are significantly reduced. It should be noted that today, in order to reduce the number of infected patients, medical practice Only blood plasma that has been sterilized is used, and it must have a certain concentration.

The role of plasma in liver function

Stable liver performance is impossible without the presence of certain elements contained in plasma. An important factor is how exactly the plasma enters the nephron tubule. The process of plasma entering the nephron tubule occurs through ultrafiltration. Everything is done under strong pressure due to the fact that the diameter of the arteries is different. To understand the whole process and find out exactly how plasma enters the nephron tubule, you can read several scientific articles, but in principle it is not necessary to do this, you just need to know the basics.

If the substance enters the nephron tubule correctly, then no problems are observed. However, if something goes wrong and the plasma does not enter the nephron tubules, then problems may occur associated with insufficient nutrition of cells and tissues, all types of proteins will not contribute to the formation of amino acids, and the kidneys will not be able to quickly distribute everything throughout the body medicines entering the body.

The volume of human plasma is equal to 55-60% of the total blood volume. To separate blood cells from plasma, sedimentation or centrifugation of blood is used after preliminary addition of a substance that inhibits its clotting. how the heavier ones settle to the bottom of the test tube, forming a red layer, and above them there is a thin colorless or whitish layer of lighter and blood platelets (), and above the formed elements there is a transparent, colorless or slightly yellowish layer of plasma.

In humans, blood plasma contains 90-91% and 9-10% dry residue, which contains and. Proteins make up 6.6-8.2% of plasma in adults, or about 3/4 of its dry residue. It contains 4-4.5% albumin, 2.8-3.1% globulin and 0.1-0.4% fibrinogen.

The blood plasma of a horse contains 2.7% albumin and 4.6% globulin, in a bull - 3.3 and 4.1%, in a pig - 4.4 and 3.9%. The protein coefficient, or the ratio of albumin to globulins (equating the number of globulins to one), in humans ranges from 1:1.5 to 1:2.3.

The total amount of protein in human blood increases in winter and decreases in summer.

The amount of proteins in plasma in autumn is less than in spring, which depends on the nature of nutrition.

In an adult total quantity Plasma protein decreases with age, regardless of nutrition. At the same time, the relative content of albumins decreases, and globulins increases. Women have slightly more globulins than men.

Globulins provide protective properties blood. Fibrinogen, a globulin, has an important biological significance, as it participates in blood clotting. It is also formed by the liver.

There are intermediates in blood plasma that can be isolated from the filtrate after all proteins have precipitated. These include urea, uric acid, amino acids, creatinine, ammonia, etc.

Blood plasma also contains glucose, lactic acid, fat, fatty acids and fat-like substances. On an empty stomach, human plasma contains 0.1-0.12% (100-120 mg%) glucose and about 0.5-1% fat and fat-like substances. Maximum quantity cholesterol in healthy people in winter and autumn (200-250 mg%), minimum - in spring and summer (170-180 mg%).

After eating food, the amount of glucose in a person’s plasma can increase to 0.2%, i.e., nutritional (dietary) hyperglycemia is observed. A decrease in plasma glucose below is called hypoglycemia. An increase in the amount of glucose above 0.2%, and a decrease below 0.05% causes severe violations body functions and leads to death.

At rest, the amount of lactic acid in the blood is 10-30 mg%. With increased physical work it increases several times, and the content also increases phosphoric acid and its connections with metabolic products of proteins and carbohydrates.

There are various types in the blood. Some are found only in plasma, others in formed elements. Plasma contains amylases that break down carbohydrates, lipase that breaks down fats, and oxidases and peroxidases involved in redox processes.

Main plasma electrolytes (on average, in milligram percent): Na – 280 – 350, L – 18 – 20, Ca – 9 – 11, Mg – 1 – 3, Cl – 320 – 360, HCO 3 – 160, SO 4 – 22, HPO 4 – 10.

In addition, human blood plasma contains: iodine - 0.002-0.013 mg%. Bromine – 0.5-1.5 mg%. Red blood cells also contain iron (in combination with proteins) - 50-60 mg%.

Spectral analysis of flowing blood made it possible to discover that the breakdown of carbohydrates without the participation of oxygen, the breakdown of compounds containing phosphorus, and the separation of ammonia from protein compounds occur in it.

When proteins foreign to the body are introduced into the blood, protective protein enzymes appear in it, breaking down these proteins - proteases which have specificity. They break down exactly the protein that is introduced into the body.

When fibrinogen, which is converted into fibrin during coagulation, is removed from plasma, serum is obtained. Whole blood lacking fibrinogen is called defibrinated. It consists of formed elements and serum.

In coelenterates and lower worms, the delivery of nutrients to the body cells and the removal of residual metabolic products is carried out by aqueous fluid - hydrolymph. In some invertebrates it contains protein substances that carry oxygen. In arthropods, hemolymph circulates in open vessels, which contains more proteins and inorganic substances than hydrolymph. Dissolved in the hemolymph are blood pigments (chromoproteins), which perform respiratory function, and it simultaneously carries out the function of lymph.

Blood plasma represented by its liquid part, which contains shaped elements. Plasma in the blood contains from 50 to 60% depending on various factors. Its acid-base balance is approximately 7.35 pH. This liquid is a slightly cloudy yellow or transparent homogeneous substance, which, after the process of sedimentation of formed elements, collects in the upper part of the vessel. Plasma is also the intercellular substance of blood and adipose tissue.

The composition of blood plasma includes water (more than 90%), proteins, which make up about 7% of its mass, mineral and organic compounds. Albumins, globulins and fibrinogens are the main proteins that make up plasma; dozens of other proteins are also included in its composition. Fibrinogen - this is the most important protein involved in blood clotting, which as a result of this process turns into fibrin . After blood plasma is called, it contains what are called immunoglobulins. Various nutrients,, final and intermediate products, inorganic ions.

Collection of donor plasma – important point, to which extensive practice is devoted. To collect it, the method is used plasmapheresis. Its essence is as follows. The donor's blood is purified from red blood cells, are collected in a special container and then returned to the blood donor.

Blood plasma, which is rich platelets, finds today wide application in medical practice as stimulation and healing of tissues after various destructive factors. Platelet-rich plasma currently forms the basis of a multifunctional technique used in cosmetology and dentistry. Also, medicinal and cosmetic preparations are prepared from the blood plasma of animals and humans: albumin, dried blood plasma, fibrinogen etc. IN lately The use of not whole whey, but its fractions and components, is more widely used.

For scientific research and for the diagnosis of certain diseases, special sera can be used - labeled with phosphors, radionuclides or enzymes.

Plasma transfusion can be used for fast healing burns, liver cirrhosis, purulent-septic diseases. Plasma transfusion begins with a test to determine the compatibility of the blood of the patient and the donor.

The administration of even small volumes of blood plasma (up to 50 ml) together with coagulation drugs gives good results during bleeding, vascular tone increases. In addition to stopping bleeding, blood plasma transfusion is used to compensate for the lack of any elements of the blood or its liquid part.

In the event that the patient has increased coagulability, transfusion is not done due to the risk of complications, including death.

The study of blood plasma has great value for diagnostics various pathologies and diseases, for example diabetes mellitus , when deviating from normal level blood ingredients, when pathological proteins appear, for example, C-reactive protein is formed.

Blood plasma is a viscous, homogeneous liquid of light yellow color. It makes up about 55-60% of the total blood volume. It contains blood cells in the form of a suspension. Plasma is usually clear, but after ingestion fatty foods may be slightly cloudy. Consists of water and mineral and organic elements dissolved in it.

Plasma composition and functions of its elements

Most of the plasma is water, its amount is approximately 92% of the total volume. In addition to water, it includes the following substances:

• proteins;
• glucose;
• amino acids;
• fat and fat-like substances;
• hormones;
• enzymes;
• minerals (chlorine, sodium ions).

About 8% of the volume is proteins, which are the main part of plasma. It contains several types of proteins, the main ones being:

• albumins – 4-5%;
• globulins – about 3%;
• fibrinogen (belongs to globulins) – about 0.4%.

Albumen

Albumin is the main plasma protein. It has a low molecular weight. Content in plasma is more than 50% of all proteins. Albumin is formed in the liver.

Protein functions:

• perform a transport function - transport fatty acids, hormones, ions, bilirubin, medications;
• take part in metabolism;
• regulate oncotic pressure;
• participate in protein synthesis;
• reserve amino acids;
• deliver medications.

A change in the level of this protein in plasma is an additional diagnostic sign. The liver condition is determined by the albumin concentration, since for many chronic diseases This organ is characterized by its decline.

Globulins

The remaining plasma proteins are classified as globulins, which are large in molecular weight. They are produced in the liver and in the organs of the immune system. Main types:

• alpha globulins,
• beta globulins,
• gamma globulins.

Alpha globulins bind bilirubin and thyroxine, activate the production of proteins, transport hormones, lipids, vitamins, and microelements.

Beta globulins bind cholesterol, iron, vitamins, transport steroid hormones, phospholipids, sterols, zinc and iron cations.

Gamma globulins bind histamine and participate in immunological reactions, which is why they are called antibodies, or immunoglobulins. There are five classes of immunoglobulins: IgG, IgM, IgA, IgD, IgE. Produced in the spleen, liver, lymph nodes, bone marrow. They are different from each other biological properties, structure. They have different abilities to bind antigens, activate immune proteins, have different avidity (rate of binding to antigen and strength) and ability to pass through the placenta. Approximately 80% of all immunoglobulins are IgG, which have high avidity and are the only ones capable of penetrating the placenta. IgM is synthesized first in the fetus. They are also the first to appear in the blood serum after most vaccinations. They have high avidity.

Fibrinogen is a soluble protein that is produced in the liver. Under the influence of thrombin, it is converted into insoluble fibrin, due to which a blood clot is formed at the site of vessel damage.

Other proteins

In addition to the above, plasma also contains other proteins:

• complement (immune proteins);
• transferrin;
• thyroxine-binding globulin;
• prothrombin;
• C-reactive protein;
• haptoglobin.

Non-protein components

In addition, blood plasma includes non-protein substances:

• organic nitrogen-containing: amino acid nitrogen, urea nitrogen, low molecular weight peptides, creatine, creatinine, indican. Bilirubin;
• organic nitrogen-free: carbohydrates, lipids, glucose, lactate, cholesterol, ketones, pyruvic acid, minerals;
• inorganic: sodium, calcium, magnesium, potassium cations, chlorine anions, iodine.

The ions in the plasma regulate the pH balance and maintain the normal state of cells.

Functions of proteins

Proteins have several purposes:

• homeostasis;
• ensuring the stability of the immune system;
• maintaining the aggregate state of the blood;
• nutrient transfer;
• participation in the process of blood clotting.

Plasma functions

Blood plasma performs many functions, including:

• transportation of blood cells, nutrients, metabolic products;
• binding of liquid media located outside the circulatory system;
• making contact with body tissues through extravascular fluids, thereby achieving hemostasis.

Donor plasma saves many lives

Use of donor plasma

In our time, transfusions often require not whole blood, but its components and plasma. Therefore, blood transfusion centers often donate blood for plasma. It is obtained from whole blood by centrifugation, that is, the liquid part is separated from the formed elements using a machine, after which the blood cells are returned to the donor. The procedure lasts about 40 minutes. The difference from donating whole blood is that blood loss is much less, and you can donate plasma again after two weeks, but no more than 12 times during the year.

From plasma, blood serum is obtained, which is used in medicinal purposes. It differs from plasma in that it does not contain fibrinogen, but contains all the antibodies that can resist pathogens. To obtain it, place sterile blood in a thermostat for an hour. Then the resulting clot is peeled off from the wall of the test tube and kept in the refrigerator for a day. After this, using a Pasteur pipette, the settled whey is poured into a sterile container.

Conclusion

Blood plasma is its liquid component, which has a very complex composition. Plasma performs important functions in the body. In addition, donor plasma is used for transfusions and the preparation of therapeutic serum, which is used for the prevention and treatment of infections, as well as in diagnostic purposes to identify microorganisms obtained during analysis. It is considered more effective than vaccines. Immunoglobulins contained in serum immediately neutralize harmful microorganisms and their metabolic products, and passive immunity is formed faster.