White blood cell
White blood cells (also called leukocytes or immune cells) are a component of blood. They help to defend the body against infectious disease and foreign materials as part of the immune system. There are normally between 4x109 and 11x109 white blood cells in a litre of healthy adult blood.
|Table of contents|
3 Other tissue cells
4 External links
There are many types of white blood cells.
Granulocytes are a category of white blood cells, characterised by the fact that all types have differently staining granules in their cytoplasm on light microscopy. There are three types of granulocytes: neutrophils, basophils and eosinophils (named according to their staining properties).
Lymphocytes are much more common in the lymphatic system, and include the so-called "killer T-cells". The blood has three types of lymphocytes: B cells, T cells and natural killer cells. B cells make antibodies that bind to pathogens to enable their destruction. CD4+ (helper) T cells co-ordinate the immune response (they are what become defective in an HIV infection). CD8+ (cytotoxic) T cells and natural killer cells are able to kill cells of the body that are infected by a virus.
Monocytes share the 'vacuum cleaner' function of neutrophils, but are much longer lived as they have an additional role. Monocytes, and their tissue counterpart macrophages, present pieces of pathogens to T cells so that they may be recognised again and killed, or so that an antibody response may be mounted.
Other tissue cells
|Health science - Medicine - Hematology|
|Hematological malignancy and White blood cells|
|Lymphoma (Hodgkin's disease, NHL) - Leukemia (ALL, AML, CLL, CML) - Multiple myeloma - MDS - Myelofibrosis - Myeloproliferative disease (Thrombocytosis, Polycythemia) - Neutropenia|
|Red blood cells|
|Anemia - Hemochromatosis - Sickle-cell anemia - Thalassemia - other hemoglobinopathies|
|Coagulation and Platelets|
|Thrombosis - Deep venous thrombosis - Pulmonary embolism - Hemophilia - ITP - TTP|
|Cardiovascular system - Blood||Edit|
|Red blood cells - White blood cells - Platelets - Blood plasma|
|White blood cells|
|Granulocytes (Neutrophil granulocytes, Eosinophil granulocytes, Basophil granulocytes) - Lymphocytes - Monocytes|
|To be filled - FVIII- vWF|
|Humoral immune system - Cellular immune system - Lymphatic system|