Lymphocytes are white (colourless) blood cells developing in lymphoid tissue and belonging to the group of non-granular leukocytes (agranulozitos). The size of the majority of lymphocytes - 7-10 MK, and shirokopolosnykh - 12-15 MK. On the painted Romanovsky - Giemsa smears lymphocytes round shape (Fig., 1-4). Round or bobowicko kernel, takes up most of the cell, intensely colored with separate lighter areas. The cytoplasm of lymphocytes surrounds the nucleus in the form of narrow light blue bezel, preveleges to the kernel. Shirokopolosnykh lymphocytes she was pale blue. Part of lymphocytes in the cytoplasm contains several large cherry-red (azurophilic) seeds.

Lymphocytes: 1-4 - lymphocytes normal human blood; 5 and 6 - lymphoblasts from the blood of patients with chronic lymphocytic leukemia.

Stage of development of lymphocytes: the lymphoblasts (Fig., 5 and 6), polimiozit and lymphocyte. The lymphoblasts and prolymphocyte appear in the blood when lymphocytic leukemia. Lymphocytes play an important role in humoral immunity (see), fixing toxins and participating in the formation of antibodies. They participate in the processes of exclusion of transplanted tissues. The blood of healthy people contains 1000 -2800, on average, 1500 lymphocytes. 1 mm3 (20-35%). Lymphocytosis (increase in the number of lymphocytes) and lymphopenia (decrease) more likely to have a relative (see WBC), depending on fluctuations in the number of granulocytes, and are not themselves the diagnostic value. Absolute lymphocytosis observed in the period of recovery from acute infectious diseases, infectious mononucleosis, infectious limfotsitoz, leukemia, thyrotoxicosis and other Absolute lymphopenia - by radiation sickness (see), in systemic lesions of the lymphatic system (generalized tuberculosis of the lymph nodes, chlamydia, sometimes lymphosarcomatous).

Lymphocytes (lymph + GK. kytos - cell) - cells related to non-granular leukocytes (agranulozitos). They make up 25-30% of all white blood cells (1500-2200 1 mm3 blood). There are small (7-9 MK), medium (10-14 MK) and large lymphocytes (15-20 MK) (Fig.). In the blood of healthy adults are mainly small lymphocytes. They have dark kernel containing many butirobetaina, located in large gubkami, and a large number of DNA. The kernel form of round, oval or borovina (small lymphocytes often round). Protoplasm is located narrow bezel and because of the expressed basophilia turns blue. In large and medium-L. protoplasmic bezel is much wider. Around the core, there is a bright perinuclear area.
The grain in the cytoplasm of L. is usually absent, can meet and Auroville grain dark cherry. Electron microscopy of Leningrad appear in the form of round or oval cells with homogeneous dark nucleus and the rim of protoplasm.
Cytoplasm poor cellular organelles; mitochondria short, thick and can surround the core. Lymphocytes have limited amoeboid motility, forming short pseudopodia or taking when driving pear shape. In motion participate cytoplasm and nucleus.
L. formed in lymphoid tissue (lymph nodes, spleen, tonsils, Peyer's patches and so on). L. thymus gland, apparently, different from formed in the lymph nodes. Develop lymphocytes of lymphoblasts. Cycle of maturing L. not been studied with absolute accuracy, but it is believed that large and medium-sized L. less Mature than the small. The life of L. installed using the labeled DNA of 100 - 200 days, but in the blood of about 20% of the cells have an age equal to 3-4 days.
The function of lymphocytes long time was unclear. It is now established that HP is involved in the formation of antibodies (along with the plasma cells) with the introduction of the alien body protein (antigen). When antibodies are formed, first of all in the relevant regional lymph nodes and then appear in the blood. The introduction of the antigen causes the increase in the number of L. and hyperplasia of lymphoid tissue with sharp increase in extracts of lymph nodes RNA. L. contain globulin, identical gamma globulin plasma, which is associated with the formation of antibodies. The release of antibodies from the cells, apparently, is under the control of the pituitary-adrenal axis. L. are carriers and may place the Deposit of nucleic acids. They take part in the destruction of toxic products of protein metabolism and play a role in the transfer of fat, that absorb in the small intestine. HP find in the inflammation, mainly chronic.
The increase in the number of lymphocytes is called limfotsitoz. There are lymphocytosis relative (percentage increase) and absolute (the increase in the absolute number HP). Most often lymphocytosis occurs in acute infectious diseases (whooping cough, infectious mononucleosis, smallpox), recovery from acute infections and intoxications, benign flowing tuberculosis, thyrotoxicosis; lymphatic leukaemia. Relative lymphocytosis observed in most States, flowing with neutropenia.
A reduction in the content of lymphocytes called limfopenia and may meet at the beginning of many acute infections, in miliary TB and in all diseases where there is the replacement of the lymphoid tissue (chlamydia, lymphosarcomatous).

Lymphocytes: 1-4 - lymphocytes normal human blood; 5 and 6 - lymphoblasts from the blood of patients with chronic lymphoid leukemia.