What blood, everyone knows.We see it as damaging the skin, for example, if you cut or pricked.We know that it is thick and red.But what is in the blood?It knows not everyone.Meanwhile, its structure is complex and heterogeneous.It is not just a red liquid.Color gives her is not the plasma and uniform particles in it.Let's see, what is our blood.
What is blood?
whole blood volume in the human body can be divided into two parts.Of course, this division is conditional.First part - peripheral, that is the one that flows in the arteries, veins and capillaries, the second - the blood which is in the hematopoietic tissues and organs.Naturally, it is constantly circulated through the body, and because it is a formal separation.Human blood is composed of two components - plasma and uniform particles that are therein.This erythrocytes, leukocytes and platelets.They differ from each other not only in the structure, but also performs the function in the body.Some particles more some less.Furthermore shaped components in human blood detected different antibodies and other particles.Normally, blood is sterile.But in pathological processes infectious nature it is possible to detect bacteria and viruses.So, what is in the blood, and in what proportions are the components?This question has long been studied, and the science of precise figures.In adults the amount of the plasma is between 50 and 60%, and the formed components - from 40 to 50% of the whole blood.Is it important to know?Of course, knowing the percentage of red blood cells or white blood cells in the blood, it can assess the state of health.The ratio of the formed particles to the total volume of blood is called hematocrit.In most cases it is not oriented at all components, but only on the erythrocytes.This rate is determined by a graduated glass tube, which is placed in the blood and centrifuged.Thus heavy components sink to the bottom, and the plasma, on the contrary, rises.The blood as it exfoliates.After that technicians can only calculate what part takes one or the other component.In medicine, these tests are widely used.At the moment they are made on automated hematology analyzers.
blood plasma
Plasma - is the liquid component of blood in which the cells are suspended, proteins and other compounds.According to her, they are delivered to organs and tissues.What is in the blood plasma?About 85% - is water.The remaining 15% are organic and inorganic substances.Also, in blood plasma are gases.This, of course, carbon dioxide and oxygen.At the inorganics have 3-4%.This anion (PO43-, HCO3-, SO42-) and cations (Mg2 +, K +, Na +).The organic materials (about 10%) are divided into nitrogen-free (cholesterol, glucose, lactate, phospholipids) and nitrogen-containing substances (amino acids, proteins, urea).Also found in the blood plasma of biologically active substances: enzymes, hormones and vitamins.They account for about 1%.In terms of histology plasma - this is nothing like intercellular fluid.
Erythrocytes
So, what is in a person's blood?Besides plasma therein and are shaped particles.Red blood cells, red blood cells or, perhaps, the largest group of these components.Red blood cells in the mature state does not have a nucleus.In form they resemble biconcave discs.The period of their life is 120 days, after which they are destroyed.This occurs in the spleen and liver.The red blood cells contain important protein - hemoglobin.It plays a key role in the process of gas exchange.These particles occurs transport oxygen and carbon dioxide.It makes the blood protein hemoglobin red.
Platelets
What is human blood, plasma and red blood cells in addition?It contains platelets.They are of great importance.These small non-nuclear cells with a diameter of 2-4 micrometer play a crucial role in thrombosis and homeostasis.Platelets are disk-like shape.They circulate freely in the bloodstream.But their distinguishing feature is the ability to be responsive to the vascular injury.That is their primary function.When injury of the blood vessel wall, they connect with each other, "close up" the damage to form a very dense clot that prevents blood flow.Platelets are formed after the fragmentation of their larger predecessors megakaryocytes.They are found in the bone marrow.A total of one megakaryocyte produces up to 10,000 platelets.This is a fairly large number.The lifespan of platelets is 9 days.Of course, they can survive and less as die during blockage in a blood vessel damage.The old split platelets in the spleen during the phagocytosis by the liver and by Kupffer cells.
Leukocytes White blood cells, or white blood cells - are agents of the immune system.This is the only particle of those that is part of the blood, which can leave the bloodstream and enter the tissue.This ability to actively contribute to the fulfillment of its primary function - protection against foreign agents.White blood cells destroy pathogenic proteins and other compounds.They are involved in immune reactions, thus producing T-cells able to recognize viruses, foreign proteins and other substances.Also lymphocytes isolated B cells producing antibodies and macrophages devouring major pathogenic cells.It is important in the diagnosis of diseases of the blood to know.It increased the number of white blood cells in it indicates the inflammation.
Government hematopoiesis
So, reviewing the composition and function of blood, left to figure out where its core particles are formed.They have a short shelf life, so you need to constantly update them.Physiological regeneration of blood components is based on a process of destruction of old cells and, consequently, the formation of new ones.This occurs in the organs of hematopoiesis.The most important of them is a human bone marrow.He is in the long bone and pelvic bone.The blood is filtered in the spleen and liver.These bodies also carried out its immunological control.
