Separate leucocytes physiology.

Neutrophils – are produced in bhone-marrow, live 8-10 hours, part of them are in circulation, another one – into marginal state and significant part leaves blood and dies in tissues. Functions:

• participating in phagocytosis;

• apoptosis triggering;

• interleukines-1,6,8 and 12 formation;

• interpherone formation;

• immune reactions;

• participation in mitosis;

• reparational and regenerational processes;

• haematopoietic reactions;

• blood coagulation;

• fibrinolysis (they contain plasminogen activator).

Neutrophilesis – amount increasing – sign of inflammational process.

Neutropenia – amount decreasing:

• viruse diseases;

• roentgen and radiorays action.

Basophils – are formed in bone-marrow, live up to 12 hours. Their relatives - fat cells (mast cells, mastocytes) live for years. Role:

• anticoagulation - heparin production;

• hystamine – allergy reactions, migraine;

• hyaluronic acid – participates in membrane permeability increasing;

• platelets activation factor synthesis;

• thromboxanes production – see next lection;

• leucotryens – participate in multiple organism reations;

• prostaglandines – the same + next lecture.

Basophily - basophils amount increasing:

• menstruations;

• allergy;

• stress;

• leucosis;

• inflammation.

Eosinophils – are produced in bone-marrow, live from 4 to 12 days. They are only several hours in blood stream, then penetrate into the tissue for destruction. Functions:

• phagocytosis;

• antitoxic function;

• kallikrein-kinin system components activation.

Eosinophily- their amount increasing:

• allergic diseases;

• haelmintoses;

• rose sundown of speedy recovery after infectious pathology – very favourable and long-awaited diagnostic criterium.

Eosinopeny – their amount decreasing:

• hard infectional diseases – unfavourable diagnostic sign.

Monocytes – are formed in different haemopoietic organs:

• bone marrow,

• lymphatic nodes;

• connective tissue.

Life duration – 36-104 hours. They leave tissues and form macrophagal family there. Role:

• strong phagocytosis;

• contain monokines influencing on lymphocytes;

• antiinfectional action;

• antitumorogenic activity;

• blood coagulation;

• fibrinolysis;

• complement system components synthesis.

Monocytosis – monocytes amount increasing:

• infectious diseases;

• fester (pus) processes;

• tuberculosis;

• haelminthes.

Lymphocytes – are originated from bone marrow and come into circulation. There one of their population comes to thymus where their differentiation in T-lymphocytes takes place. Other part – to bursa of Fabricius analogue (in birds) in small intestine cellular formations, tonsills, appendix, bone marrow and are differentiated in lymphocytes (bursa-dependent). This lymphocytic part is not differentiated in immune organs and such lymphocytes are calles zero-lymphocytes (neither T-, nor B-).

T-lymphocytes have several types. In a whole, they are responsible for cellular immunity. Their amount is 40-70 per cent of all lymphocytes amount.

B-lymphocytes also have several types. They provide immunoglobulins formation and thus delt with cellular and especially with humoral immunity. Their amount is 20-30 per cent of all lymphocytes.

Zero-lymphocytes secrete proteins (perphorines) possessing the ability to make the foramen in side cells membrane and while protheolytic enzymes (cytolysines) pouring in them destroy them. That’s why they are often named as natural killers. Their amount is 10-20 per cent of all lymphocytes.

Main white blood cell function is to participate in defense organism reactions against foreign agents. There exist the natural (non-specific) and specific defence forms.

The non-specific defence is directed to any foreign agent eliminating. The phagocytosis, the complement system and others humoral defense factors are the main types of such reactions. Phagocytosis consists of engulfing the microbes and cells via the formation of the pseudopods followed by endocytosis of the phagocytic vesicle. Next, the endocytotic vesicle is incorporated into the lysosomes of the phagocytes where the microbes and cells are digested by lysosomal enzymes. This phenomenon is adequate to the neutrophiles, monocytes, eosinophiles, macrophages and thrombocytes. In the course of the phagocytosis process we differentiate such stages as the phagocyte approaching to the phagocytized object (or ligand), the ligand contact with the phagocyte membrane, the ligand engulfing, digestion and destruction of the phagocytized object. The phagocytes find their way to the site of injury by chemotaxis or similar guiding mechanisms.

Complement system - is a special enzyme system consisting of the proteins (more than 20 types). In includes 9 components (C1…C9). During the activation process some of its components are cleaved in the fragments influencing directly the course of specific and nonspecific defense reactions. There exist the classical and alternative ways of complement system activation. The destruction of foreign and old cells, the phagocytosis and the immune reactions course activates, the vessel wall permeability increases, the blood coagulation hastens at the complement system activation that influence the pathological process.

The other humoral defense factors – defense reactions connected with the action of such substances as lysozyme and interferon. Lysozyme as a protein possesses the enzyme activity suppressing the growth and the development of causative agents and destroying some of the microorganisms. It can be found in nasal mucosa, intestines, salivary secret, lacrimal fluid etc. In small amounts one can find it in the granules of polymorphonuclear leukocytes, in macrophages and when destroyed they fall into the extracellular fluid. Interferon as the globulin of blood plasma can be located in the lymphocytes providing antiviral defense and delaying the cancer cell growth.

Specific defense – immunity – is a reaction complex directed to maintaining the homeostasis on meeting the host’s body with the antigens which are considered as foreign (despite their forming in the organism itself or if they come into it from outside). Under the action of antigen the host body forms the antibodies, activates lymphocytes and thus they get the ability to participate in the immune response. This antigen ability to cause the specific immune response is due to the presence of multiple determinants on its molecule. The active centers of forming antibodies specifically correspond to the determinants like the key to the lock. The antigen interacting with its corresponding antigen forms the immune complex.

The immune organs are divided into central (thymus, bursa of Fabricius, bone marrow) and the peripheral (lymphatic nodes, spleen etc.). There are two categories of acquired immune responces – humoral or antibody-mediated and cell-mediated.

In addition to the above mentioned information we can say that not only the nervous and humoral regulation of various organism functions but the immunological one exist in the human body. Thus, the lymphokines and monokines secreted by the lymphocytes, the monocytes and the macrophages are capable of changing the central nervous system, the heart, the vessels, the respiratory and digestive organs action. As for the interleukines they are involved in all the physiological body reactions. The immune system itself is not only the defense system (especially the antiinfectious) but the important regulative system too. Functionally it is tied with both nervous and the endocrine organism system. Such an approach to functionning of this system not only extends our data about its activity but permits to outline the new therapy ways of acquired and hereditary disorders.