This theme, like the blood and the function of blood, definitely merits attention, as one of the foundations reveals the full operation of the entire human body.Understand the value of the blood flow is important because of its significant impact on all of the key processes in the body.
What blood
under the blood liquid is understood the internal environment, which provides a constant key biochemical and physiological parameters, while promoting humoral link between the bodies.By studying the blood, its composition and functions, it is important to understand the essence of the two basic terms:
- peripheral blood (it consists of plasma);
- forming elements (located inside the blood in suspension).
Blood can also be defined as a form of fabric, is characterized by several features: its constituent parts have different origins, this body fluid is in constant motion, all the elements of the blood are formed and destroyed outside of the blood flow.
Under the theme: "The system of blood, structure and function," it is worth noting that with this system include the bodies and kroverazrusheniya hematopoiesis (liver, bone marrow, lymph nodes, spleen), and peripheral blood.Composition of the blood
more than half of the blood - 60% - of the plasma, and only 40% filled with items such as red blood cells, white blood cells and platelets.Viscous, thick liquid (plasma) contains substances that are important for the functioning of the body.They move on tissues and organs, providing the desired chemical reaction and a full activity of the entire nervous system.Produced by glands of internal secretion of hormones get into the plasma and then spread throughout the body blood flow.Antibodies - enzymes that protect the body from various types of threats - are contained in the plasma.
Erythrocytes
Considering the structure and basic functions of the blood, you must pay attention to the red blood cells.It's red blood cells that determine the color of blood.Its structure is very similar to an erythrocyte thin sponge in which the pores is hemoglobin.On average, each red blood cell is capable of transferring 267 million particles of hemoglobin, "swallows" carbon dioxide and oxygen, entering them into the mix.
Delving into the theme: "The composition and function of blood: red blood cells," we must understand that these particles can transport a large amount of hemoglobin due to a nuclear-free structure.Regarding the size of the erythrocyte, then they reach 8 micrometres in length and 3 micrometers in width.The number of red blood cells, without exaggeration, is huge: every second bone marrow produced more than 2 million of these particles, their total mass in the body is about 26 trillion.
leukocytes
These elements are also integral components of the blood flow.Leukocytes called white blood cells, the amount of which may differ.They have rounded irregular shape.Because white blood cells - a particle having the core, they are able to move independently.They are much smaller than the erythrocytes, but the leukocytes are actively involved in the function of protecting the body from infections.The composition of the blood and blood function can not be complete without the white blood cells.
Leukocytes possess special enzymes that are able to bind and cleave the decomposition products and foreign proteins, as well as to absorb dangerous microorganisms.In addition, some forms of white blood cells can produce antibodies - protein particles that carry out one of the most important functions: Defeat all alien organisms caught in the blood, mucous membranes and other tissues or organs.
Platelets
These platelets are moving very close to the walls of blood vessels.Their main function - recovery vessels in case of damage.If use medical terminology, we can say that platelets are actively involved in providing hemostasis (blood coagulation).In one cubic millimeter of an average of more than 500 thousand. These particles.Platelets live less than other elements of blood - from 4 to 7 days.
They move freely with the blood flow and retained only in those places where the flow of blood goes into a quiet state (spleen, liver, subcutaneous tissue).Upon activation of platelets becomes a spherical shape, wherein formed pseudopodia (special protuberances).It is through these pseudopodia blood elements are capable of connecting with each other and fixed to the site of injury of the vessel wall.
composition of blood and blood function should be considered only on the basis of action of platelets.
Lymphocytes
This term refers to small mononuclear cells.Lymphocytes in the majority have a size up to 10 microns.Nuclei of the cells are round and compact, and is composed of small cytoplasmic granules and colored in bluish color.A superficial study of it can be seen that all cells have the same form.It does not change the fact that the next - they differ in the properties of the cell membrane and its functions.
These mononuclear blood elements are divided into three main categories: 0-cells, B-cells and T-cells.The lymphocyte function is to serve as precursors to cells that form antibody.In turn, the T-cells provide the transformation of B leukocytes.It should be noted that the T lymphocytes - a specific group of cells of the immune system which fulfills several important functions.For example, the process of their synthesis involving macrophage activation factors, and growth factors, interferons, as well as B cells.Inductor can be isolated and T cells that are involved in the stimulation of antibody formation.For example, the action of various categories of lymphocytes is clearly visible interconnection structure and function of blood.
As for the 0-cells, they are significantly different from the others, because they have no surface antigens.Some of these elements act as Blood "natural killer" destroying those cells that have the structure of the cancer or infected with the virus.Blood plasma
The composition includes blood plasma water (90-90%) and the solids: proteins, fats, glucose, various salts, metabolites, vitamins, hormones, and others. One of the key features is the plasma osmotic pressure.Also plasma carries nutrients, blood cells and metabolic products.By studying the structure and function of blood plasma , you will notice that it serves as a link between the liquids that are outside of the blood vessels.
Plasma permanent contact with the kidneys, liver and other organs, thereby maintaining homeostasis - constancy of the internal environment.
Physical and chemical properties of blood
studying a topic such as composition, properties and functions of blood is to pay attention to certain facts.The blood volume in the body of an adult is equal to an average of 6-8% of the weight of his body.In men, this figure reaches 5-6 liters, women - from 4 to 5. It is the daily amount of blood passes through the heart 1 thousand. Times.It is worth knowing that the blood does not fill the vascular system completely, much of it remains free.The density of blood depends on the number of erythrocytes and it is about 1,050-1,060 g / cm3.The viscosity of up to 5 conventional units.
active reaction of the blood caused the ratio of hydroxyl and hydrogen ions.Specifies that the activity of such pH, as the pH (hydrogen ion concentration).Changes in pH of blood, in which the body can function to range from 7.0-7.8.If there is a shift of the active reaction of blood to the acid side, such a state may be defined as acidosis.Its development is due to an increase in the level of hydrogen ions.If the reaction is shifted to the alkaline side, it makes sense to talk about alkalosis.This change in pH is a consequence of reducing the concentration of hydrogen ions and the increase in the concentration of hydroxyl ions OH.
transport function of the blood
This is one of the key tasks performed by the bloodstream.By the process of transportation of various elements include the following functions:
- trophic: transferred to all parts of the body of nutrients, trace elements and vitamins;
- regulatory: the transportation of hormones and other substances that are part of the humoral system of regulation of the organism;
- respiratory: transfer of respiratory gases O2 and CO2 from the lungs to the tissues and in the opposite direction;
- thermoregulatory: removing excess heat from the brain and internal organs to the skin;
- excretory: metabolic products are transported to the organs of excretion.
Hemostasis
essence of this function is the following process: in the case of damage to medium or fine blood vessels (when squeezed or incision tissue) and the occurrence of external or internal bleeding at the site of the destroyed vessels form a blood clot.That it prevents significant blood loss.Under the influence of nerve impulses and the released chemicals reduces the vessel lumen.If it so happened that was damaged endothelial lining of blood vessels beneath the endothelium exposed collagen.It quickly enough adhered platelets circulating in the blood.
homeostatic and protective functions
studying the blood, its composition and function, pay attention to the process of homeostasis.Its essence is to preserve water and salt and ion balance (a consequence of the osmotic pressure), and maintaining the pH of the internal environment.
With regard to the protective function, then its essence is to protect the body by the immune antibodies, phagocytic activity of leukocytes and antibacterial substances.
system
blood circulation to the system include heart and blood vessels: blood and lymph.The key task of the blood - a timely and complete supply of organs and tissues of all the necessary elements for life.The movement of blood through the vessels of the system is ensured by pumping action of the heart.Delving into the theme: "The value of the composition and function of blood" is to identify the fact that the blood itself directly moves continuously through the vessels and, therefore, capable of supporting all vital functions, which were discussed above (transport, protection and others.).
key body in the blood is the heart.It has the structure of hollow muscular organ and by the vertical solid walls is divided into left and right halves.There is another partition - the horizontal.Its task is the separation of the heart into 2 upper chamber (atrium) and two lower (ventricles).
studying the structure and function of human blood, it is important to understand the principle of the circulation.The system of blood are two circle movement: large and small.This means that the blood within the body moves in two closed systems of vessels, which are connected to the heart.
as a starting point of a large range of acts aorta extending from the left ventricle.That it gives rise to small, medium and large arteries.They (artery), in turn, branch into arterioles, capillaries ending.Directly capillaries themselves form a wide network that permeates all tissues and organs.It is in this network is the return of nutrients and oxygen to the cells, as well as the process of producing metabolic products (carbon dioxide), including.
From the lower part of the trunk blood enters the inferior vena cava, from the top, respectively, in the top.These two vena cava and complete systemic circulation, getting into the right atrium.
Referring to the pulmonary circulation, it should be noted that he begins pulmonary trunk extending from the right ventricle to the lungs and carrying venous blood.Himself pulmonary trunk divides into two branches that go to the right and left lung.Pulmonary artery divided into smaller arterioles and capillaries, venules passing subsequently forming veins.The key task of the pulmonary circulation is to ensure the recovery of the gas composition in the lungs.
Studying the composition of blood and blood function, it is easy to conclude that it is essential for tissue and internal organs.Therefore, in the case of serious bleeding or blood disorders there is a real threat to human life.
