Life is impossible without blood. In the human body, it performs a number of important functions. There are several of them, but it is difficult to overestimate these properties. The work of the heart, organs and blood vessels depends on the state of the blood.
The functions and characteristics of the body determine the physicochemical properties of blood. To understand them, it is necessary to delve into the study of the physiology of the human body. Separately, it is necessary to consider the constituent elements of the blood, as well as the properties of the plasma.
general characteristics
A person needs blood for a number of reasons. She acts as a subspecies of connective tissue. The composition of the blood includes shaped cells and liquid substance (plasma).
The first group includes red blood cells, platelets and white blood cells. Each kind of blood cells performs certain functions. There are up to 45% of them in whole blood. Plasma is an intercellular fluid and makes up 55% of the total mass.
The ratio of shaped particles of blood to its total volume is called hematocrit. Gender affects the physico-chemical properties of blood. The physiology of males suggests a hematocrit of 41 to 48%, and for females, from 37 to 43%. Its level is regulated by various mechanisms of the human body. This may be a change in the absorption and excretion of salts, thirst, regulation of protein metabolism or the production of red blood cells.
For example, when climbing mountains, where the atmosphere becomes more rarefied, the hematocrit increases due to the need to strengthen the body's oxygen supply. The volume of blood that is in the body of an adult reaches about 5 liters. This is approximately 7% of its total mass.
Why is blood needed?
The functions and physico-chemical properties of the blood ensure the normal functioning of the human body. The main tasks of this substance include transport, regulatory, thermoregulatory qualities, as well as protective properties and maintenance of tissue regeneration.
The transport function consists of several aspects. The circulatory system carries oxygen to the tissues, taking carbon dioxide from them (respiratory function). Also related to transport qualities is the delivery of nutrients to all systems. This group also includes the excretory purpose of blood. She collects the final products of cell metabolism and transports them to the organs of excretion.
The thermoregulatory purpose of blood is to transfer heat from the place of its formation to other systems. Maintenance of tissue regeneration and their homeostasis occurs due to metabolic processes.
Blood also regulates the transfer of hormones and other substances. The protective purpose is to provide immune function. To do this, a number of processes occur in the human body.
Basic properties
In order for a person to feel good, maintaining normal all blood functions is required. But in addition to this, there are a number of indicators characterizing the health of the body. These are the basic physical and chemical properties of blood. They can be briefly listed, but each requires a more detailed consideration.
The main indicators of the state of the circulatory system are oncotic and osmotic pressure, suspension qualities. A sign such as colloidal plasma stability is also important. The main qualities that are also evaluated in a laboratory study are the density and viscosity characteristics of the blood. All of these properties should be normal, otherwise the person’s well-being worsens significantly, because blood flows through all systems, feeding every cell. Health directly depends on its characteristics.
Osmotic type of pressure
Considering the basic physical and chemical properties of blood, it is necessary first of all to pay attention to its quality, such as the osmotic type of pressure. This indicator depends on the level of concentration of dissolved substances in plasma.
These can be non-electrolytes and electrolytes. All these components exert a certain pressure. NaCl creates most of this effect. Inorganic components together account for 95% of the total osmotic pressure.
Normally, in an adult, this figure is 7.5-7.6 atm. This is the so-called saline solution, the salt content of which is 0.86%. But if the indicator of NaCl content increases, then its concentration and, consequently, pressure increase. This solution is called "hypertonic." A drop in salt concentration leads to a decrease in pressure. This leads to the appearance of a hypotonic type of solution.
Osmotic pressure deviations
Violation of the physico-chemical properties of blood relative to the osmotic pressure leads to system malfunctions. The physiological environment by this principle facilitates the passage of the solution through semipermeable membranes. Moreover, the movement is carried out from a liquid with a lower concentration of salt to a more saturated one.
With a hypertonic type of solution, red blood cells lose water, which leads to their wrinkling. If a reduced type of pressure is observed, then they increase. In this case, red blood cells may even burst. This process is called osmotic hemolysis. A lack of red blood cells is dangerous for humans.
Oncotic type of pressure
In a colloidal medium, proteins are also able to create pressure, so it is important to know the hematological chemical composition. Physico-chemical properties of blood are also considered according to the criterion of an oncotic type of pressure.
Proteins contained in plasma are difficult to overcome thin capillary vessels. Oncotic pressure allows water to accumulate in the blood. It is created mainly by albumin. Their number in plasma is the highest.
If for some reason the number of plasma albumin is underestimated, the tissues begin to swell. With an increase in their concentration, the reverse process occurs. A significant amount of water is retained in the circulatory system. Violations of this indicator are also felt by a person.
Colloidal stability
Colloidal stability, which is observed in plasma, is also included in the physicochemical properties of blood. The physiology of this process is provided by the hydration of protein molecules.
On their shell there is a double electric ion coating. They make up the so-called surface potential. It can also be due to the slip that occurs on the surface of the particle. It is carried out in solution. This process forms uniform charges on surfaces at which particles repel.
Such processes determine the stability of colloidal solutions, prevent the formation of clusters. The higher the potential value, the stronger the protein particles move away from each other.
The degree of stability of this solution is called the zeta potential. Due to the predominant plasma content of all proteins namely albumin, colloidal stability depends mainly on them.
Suspension qualities
Studying the physicochemical properties of blood, attention should be paid to suspension qualities. They are associated with plasma protein stability. Cell units should normally be kept in suspension. The erythrocyte sedimentation rate (ESR) is the main criterion for the suspension properties of blood.
Assessment of this process is carried out in a motionless blood volume. Albumin is adsorbed on the surface of red blood cells. The more they accumulate, the more suspension capacity increases.
If the blood level of globulins or other large molecular unstable proteins rises, then ESR will increase. Suspension properties are reduced. The norm of this indicator in men is 5-11 mm / h, and in women - 6-12 mm / h.
Blood viscosity
Physico-chemical properties of blood are studied in the context of its viscosity characteristics. They are important no less than other indicators.
Viscosity is the ability of some particles relative to others to resist fluid movement due to friction. This is a complex process of interaction in the composition of blood water, colloid molecules on the one hand, shaped elements and plasma on the other.
Plasma viscosity for this reason differs significantly from that of blood. They can be compared with respect to water. In this case, the plasma viscosity is 1.9-2.4 times higher, and 5 times higher for blood. If the number of red blood cells increases, the number of hematocrit increases, and the viscosity increases.
Viscosity increase
Deviations are possible in the viscosity index, which characterizes the physicochemical properties of blood. Pathophysiology considers this process in a complex. In addition to an increase in red blood cells, a change in plasma can also affect it. The higher the concentration of high molecular weight proteins in it, the higher the viscosity index.
Also, suspension decrease in blood quality contributes to this. If red blood cells form clusters, viscosity also increases.
Blood is a heterogeneous structure. Lowering blood pressure can also increase its viscosity. Conversely, a decrease in viscosity occurs under the influence of high pressure. Systemic structure breaks down. If the capillaries narrow to 150 microns or less, the viscosity decreases. The work of the cardiovascular system of a person directly depends on this indicator.
Specific gravity
Changes in the physicochemical properties of blood affect the functioning of each body system. On control, it is necessary to keep such a parameter as specific gravity. It depends on the number of red blood cells, as well as the hemoglobin contained in them.
The composition of the plasma, no doubt, plays an important role. The indicator of the specific gravity of blood in an adult is 1.05-1.06. In men, the number of red blood cells is higher, so this indicator in them is slightly more significant.
In conditions of increased loss of moisture by the body (for example, in hot weather, in a stuffy room), the specific gravity of blood rises. In plasma, this indicator is lower than in red blood cells. Therefore, with loss of fluid, an increase in hematocrit occurs. To bring this indicator back to normal, the brain sends a thirst signal. This allows you to replenish water supplies. Therefore, on a hot day, the need for a large amount of liquid increases.
Plasma
The physicochemical properties of blood plasma also deserve detailed consideration. Thanks to the proteins contained in it, this substance performs a number of functions.
Plasma regulates water-salt metabolism, supports osmotic pressure. This is very important for normal health. Due to oncotic pressure, it provides the necessary level of homeostasis. Thanks to plasma, viscous properties, coagulability, and protective functions are also supported.
This medium is involved in maintaining the correct level of acid-base balance. Plasma is a reserve of amino acids. This enables the blood to fulfill its nutritional functions. Hormones and fatty acids are transported in plasma.
Having examined the physicochemical properties of blood, we can understand its importance for the body. Maintaining all the characteristics at the proper level is the key to the health and proper functioning of the entire cardiovascular system. Even slight deviations in the indices and properties of blood and its plasma affect the well-being of a person.
The signals of the body must be listened to for their own good. If any components are not enough for the normal functioning of the circulatory system, a person will feel unsatisfactory. In such cases, you need to contact a hematologist.