Blood is a connecting liquid fabric which fills cardiovascular system of the person. Blood consists of uniform elements, and also liquid part — plasma. Leukocytes, and also post-cellular structures among which there are thrombocytes and erythrocytes belong to uniform elements. Blood circulation happens under the influence of rhythmic reduction of heart on system of vessels, the direct message of blood with other tissues of a body is absent because of existence of gistogematichnsky barriers. The red color has blood thanks to hemoglobin which contains in erythrocytes.

Composition of blood

As it was already stated above, blood consists of plasma, and also uniform elements. The blood plasma makes about 50-60% of total amount, and for 40-50% from uniform elements.

The Gematokritny number is a ratio of uniform elements and a blood plasma.

Blood is subdivided into peripheral blood which is in a bed of vessels, and also on blood which is in heart and bodies of a hemopoiesis.

Solutes – mineral and organic compounds, proteins are a part of a blood plasma. The main blood proteins are fibrinogens, globulins, albumine. Anions, cations which make several percent from total amount belong to inorganic matters. Organic matters of a blood plasma are provided by nitrogen-free connections (cholesterol, phospholipids, a lactate, fatty acids, glucose) and nitrogen-containing (ammonia, creatinine, urea, amino acids, proteins). Besides, to contain in a blood plasma mediators and enzymes, vitamins, hormones and other biologically active agents carbon dioxide, oxygen. The remained 85% of a blood plasma are made by water.

Uniform elements are provided by leukocytes, thrombocytes, erythrocytes.

Leukocytes are white blood cells which are part of immunity of an organism. All leukocytes are capable to go beyond a blood channel in fabric. Their main function consists in protection, in participation in immune responses. At the same time allocate T lymphocytes which distinguish various harmful substances and viruses, and also V-cells which are engaged in development of macrophages, the antibodies destroying such substances. Normal in blood of leukocytes it is much less, than other uniform elements.

Thrombocytes are red platelets which main function consists in ensuring coagulability of blood which follows from the damaged vessel, protecting thereby an organism from the blood loss which is life-threatening. This function is provided together with blood proteins, fibrinogens, for example.

Erythrocytes are red blood cells which are the most numerous among all other uniform elements. These cells do not contain a kernel in the ripened age, they have the form of a disk, convex from both parties. Erythrocytes contain hemoglobin – important protein which part iron is. It provides transport of gases, mainly oxygen.

Blood is fabric which is quickly updated. Phisiological regeneration of elements of blood occurs due to destruction of the dying and old cells, and also formation of new cells by bodies of a hemopoiesis. Marrow is just such main body. The red, or hemopoietic brain of the person, is located in long tubular and haunch bones.

The spleen is the main filter of blood. It carries out as well immunological control of blood.

The total quantity of blood makes 6-7% of body lump.

Blood which continuously circulates in the closed system of an organism carries out various functions:

  1. Protective function consists in ensuring humoral and cellular protection against alien agents.
  2. Transport function is subdivided into the following subfunctions:
  • Nutritious – delivers nutrients to cells of fabrics.
  • Respiratory – transfer of oxygen and carbon dioxide between body tissues and lungs in both directions.
  • Regulatory – ensuring humoral cellular protection of a human body against alien agents.
  • The thermoregulatory subfunction is responsible for regulation of body temperature.
  • Excretory, or secretory function, consists in transport of metabolic products to kidneys and lungs for their removal from an organism.

Intercellular liquid and lymph, are partially also capable to carry out transport function in an organism.

The blood group is a community of some antigenic properties of such blood cells as erythrocytes. Belonging to any blood group does not change throughout life, it is inborn.

The greatest value has classifications of blood by the Rhesus factor system and blood group. The Rhesus factor is defined by absence or existence on surfaces of a blood cell of special antigen therefore the organism admits "Rh-positive" or "Rh-negative". Division of blood according to groups happens on the AB0 system on which blood can be divided into 4 groups. Respect for compatibility on these indicators is especially important for safe hemotransfusion, and value of a Rhesus factor of mother and father at pregnancy is extremely necessary for avoidance a Rhesus factor conflict. For the child it is possible to define emergence of this or that blood group on the basis of blood group of parents.

Use of blood of animals is possible as in cooking, and medicines. Some medicines, such as serums and immnoglobulina are made of blood of animals, as a rule, of horses. At the same time some religions forbid use of blood of animals in food in any kind.

Section: To