Leucocytes

- larger than red erythrocytes, almost colourless

- do not contain hemoglobin

- have nucleus (real cells)

- can live for many months or years

- amount: 4-9 x10⁹ per l, newborn: 18-20x10⁹/l

- produced in the red bone marrow, the lymph nodes and the spleen

- the main function is to protect body aginst invaders and our modified cells = cancer cells

- their number depends on the actual physiological state of organism

Classifying based on their structure:

a) agranulocytes - do not have granules in their cytoplasm, contain large nucleus

   i. lymphocytes - small cells with round nucleus and little cytoplasm

• lymphocytes T > are maturing in thymus, Function : activate other leucocytes after the contact with the invader
• lymphocytes B , their function is producing antibodies after activation by lamphocytes T

   ii. monocytes - the largest of the leucocytes, they are phagocytic cells and are able to move throught the blood capillary walls = diapedesis

b) granulocytes - have large granules in their cytoplasm and contain lobed nucleus, they are classified according to their stained appearance:

• eosinophils - phagocytic cells, their number increases in allergies, (stain red), important in inflammation
• basophils - rare (stain blue), their function isn´t clear
• neutrophils - phagocytic cells (stain light pink)

HLA (human leucocyte antigen) - most important system which is based on the presence of a antigen of the surface of leucocytes or white blood cells, it has a carow transplantation

Leucocytosis - describes increased amount of leucocytes as the result of some disease

Leukemia - describes increased amount of leucocytes as the result of abnormal = carcinogenic production of leucocytes