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Encyclopedia > White blood cell
A scanning electron microscope image of normal circulating human blood. In addition to the irregularly shaped leukocytes, both red blood cells and many small disc-shaped platelets are visible
A scanning electron microscope image of normal circulating human blood. In addition to the irregularly shaped leukocytes, both red blood cells and many small disc-shaped platelets are visible

White blood cells or leukocytes are cells of the immune system which defend the body against both infectious disease and foreign materials. Several different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell. Leukocytes are found throughout the body, including the blood and lymphatic system. White Blood Cells is the third album by American rock band The White Stripes, released in 2001 (see 2001 in music). ... Image File history File links Download high-resolution version (1800x2239, 1365 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Immune system Scanning electron microscope White blood cell Platelet Neutrophil granulocyte Lymphocyte Monocyte ... Image File history File links Download high-resolution version (1800x2239, 1365 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Immune system Scanning electron microscope White blood cell Platelet Neutrophil granulocyte Lymphocyte Monocyte ... SEM Cambridge S150 at Geological Institute, University Kiel, 1980 SEM opened sample chamber The scanning electron microscope (SEM) is a type of electron microscope capable of producing high-resolution images of a sample surface. ... A 250 ml bag of newly collected platelets. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... A scanning electron microscope image of a single neutrophil (yellow), engulfing anthrax bacteria (orange). ... This false-colored electron micrograph shows a malaria sporozoite migrating through the midgut epithelia. ... Multipotent stem cells can give rise to several other cell types, but those types are limited in number. ... This article does not cite any references or sources. ... Sketch of bone marrow and its cells Pluripotential hemopoietic stem cells (PHSCs) are stem cells found in the bone marrow. ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... The human lymphatic system The lymphatic system is a complex network of lymphoid organs, lymph nodes, lymph ducts, lymphatic tissues, lymph capillaries and lymph vessels that produce and transport lymph fluid from tissues to the circulatory system. ...


The number of leukocytes in the blood is often an indicator of disease. There are normally between 4×109 and 11×109 white blood cells in a liter of blood, making up approximately 1% of blood in a healthy adult.[1] In conditions such as leukemia the number of leukocytes is higher than normal, and in leukopenia this number is much lower. The physical properties of leukocytes, such as volume, conductivity, and granularity, may change due to activation, the presence of immature cells, or the presence of malignant leukocytes in leukemia. The liter (spelled liter in American English and litre in Commonwealth English) is a unit of volume. ... Leukemia or leukaemia(Greek leukos λευκός, “white”; aima αίμα, “blood”) (see spelling differences) is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation (production by multiplication) of blood cells, usually white blood cells (leukocytes). ... Leukopenia or leukocytopenia refers to a decrease in the number of circulating white blood cells (leukocytes) in the blood. ...

Contents

Etymology

The name "White Blood Cell" derives from the fact that after centrifugation of a blood sample, the white cells are found in the Buffy coat, a thin layer of nucleated cells between the sedimented red blood cells and the blood plasma, which is typically white in color. The scientific term leucocyte directly reflects this description, derived from Greek leukos - white, and kytos - cell. Blood plasma may sometimes be green if there are large amounts of neutrophils in the sample, due to the heme-containing enzyme myeloperoxidase that they produce. Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures. ... Buffy coat is the fraction of a centrifugated blood sample that contains most of the white blood cells. ... Blood plasma is the liquid component of blood, in which the blood cells are suspended. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... Myeloperoxidase (MPO) is a peroxidase enzyme (EC 1. ...


Types

There are several different types of white blood cells. One primary technique to classify them is to look for the presence of granules, which allows the differentiation of cells into the categories granulocytes and agranulocytes: A granule is a small grain. ... Eosinophil granulocyte Basophil granulocyte Granulocytes are a category of white blood cells characterised by the presence of granules in their cytoplasm. ... Agranulocytes are a category of white blood cells characterised by the absence of granules in their cytoplasm. ...

The functions and morphology of these cells are as follows:[1] A granule is a small grain. ... A diagonal molecular slab from the DPPC lipid bilayer simulation1; color scheme: PO4 - green, N(CH3)3 - violet, water - blue, terminal CH3 - yellow, O - red, glycol C - brown, chain C - grey. ... Endocytosis (IPA: ) is a process whereby cells absorb material (molecules such as proteins) from the outside by engulfing it with their cell membrane. ... Neutrophil granulocytes (commonly referred to as neutrophils) are a class of white blood cells and are part of the immune system. ... Categories: Wikipedia cleanup | Biology stubs | Blood and immune system cells ... Eosinophils are white blood cells that are responsible for combating infection by parasites in the body. ... A granule is a small grain. ... Organelles. ... A scanning electron microscope (SEM) image of a single human lymphocyte. ... Monocyte A monocyte is a leukocyte, part of the human bodys immune system that protects against blood-borne pathogens and moves quickly (aprox. ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, from makros large + phagein eat) are cells within the tissues that originate from specific white blood cells called monocytes. ...

Type Microscopic Appearance Cartoon Approx. % in humans Description
Neutrophil 65% Neutrophils deal with defense against bacterial or fungal infection and other very small inflammatory processes and are usually first responders to microbial infection; their activity and death in large numbers forms pus. They are also known as polymorphonuclear leukocytes and microphage. The term microphage arise due to their active involvement in phagocytosis.
Eosinophil 4% Eosinophils primarily deal with parasitic infections and an increase in them may indicate such. Eosinophils are also the predominant inflammatory cells in allergic reactions. The most important causes of eosinophilia include allergies such as asthma, hay fever, and hives; and also parasitic infections.
Basophil 1% Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine causing inflammation.
Lymphocyte 25% Lymphocytes are much more common in the lymphatic system. The blood has three types of lymphocytes:
  • B cells: B cells make antibodies that bind to pathogens to enable their destruction. (B cells not only make antibodies that bind to pathogens, but after an attack, some B cells will retain the ability to produce an antibody to serve as a 'memory' system.)
  • T cells:
    • CD4+ (helper) T cells co-ordinate the immune response and are important in the defence against intracellular bacteria.
    • CD8+ cytotoxic T cells are able to kill virus-infected and tumor cells.
    • γδ T cells possess an alternative T cell receptor as opposed to CD4+ and CD8+ αβ T cells and share characteristics of helper T cells, cytotoxic T cells and natural killer cells.
  • Natural killer cells: Natural killer cells are able to kill cells of the body which are displaying a signal to kill them, as they have been infected by a virus or have become cancerous.
Monocyte 6% Monocytes share the "vacuum cleaner" (phagocytosis) function of neutrophils, but are much longer lived as they have an additional role: they present pieces of pathogens to T cells so that the pathogens may be recognized again and killed, or so that an antibody response may be mounted.
Macrophage (see above) Monocytes are able to develop into the "professional" phagocytosing macrophage cell after they migrate from the bloodstream into the tissue and undergo differentiation.

Neutrophil granulocytes (commonly referred to as neutrophils) are a class of white blood cells and are part of the immune system. ... Image File history File links PBNeutrophil. ... Image File history File links Neutrophil. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria is also the fictional name of a warring nation under Benzino Napaloni as dictator, in the 1940 film The Great Dictator... Divisions Chytridiomycota Zygomycota Ascomycota Basidiomycota The Fungi (singular: fungus) are a large group of organisms ranked as a kingdom within the Domain Eukaryota. ... Eosinophils are white blood cells that are responsible for combating infection by parasites in the body. ... Image File history File linksMetadata Eosinophil. ... Image File history File links Eosinophil2. ... A parasite is an organism that lives in or on the living tissue of a host organism at the expense of it. ... Basophil redirects here. ... Image File history File links PBBasophil. ... Image File history File links Basophil. ... This article needs cleanup. ... An antigen or immunogen is a molecule that stimulates an immune response. ... This article or section does not cite any references or sources. ... An abscess on the skin, showing the redness and swelling characteristic of inflammation. ... A scanning electron microscope (SEM) image of a single human lymphocyte. ... Image File history File linksMetadata Download high-resolution version (856x592, 71 KB) Lymphocyte (sang humain, normal). ... Image File history File links Lymphocyte. ... A scanning electron microscope (SEM) image of a single human lymphocyte. ... B cells are lymphocytes that play a large role in the humoral immune response (as opposed to the cell-mediated immune response). ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... A pathogen (literally birth of pain from the Greek παθογένεια) is a biological agent that can cause disease to its host. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... A pathogen (literally birth of pain from the Greek παθογένεια) is a biological agent that can cause disease to its host. ... T cells are a subset of lymphocytes that play a large role in the immune response. ... CD4 (cluster of differentiation 4) is a molecule that is expressed on the surface of T helper cells (as well as regulatory T cells and dendritic cells). ... A helper (or TH) T cell is a T cell (a type of white blood cell) which has on its surface antigen receptors that can bind to fragments of antigens displayed by the Class II MHC molecules found on professional antigen-presenting cells (APCs). ... CD8 (cluster of differentiation 8) is a molecule that is expressed on the surface of cytotoxic T cells. ... A cytotoxic T cell (also known as TC, CTL or killer T cell) belongs to a sub-group of T lymphocytes (a type of white blood cell) which are capable of inducing the death of infected somatic or tumor cells; they kill cells that are infected with viruses (or other... For malignant tumors specifically, see cancer. ... γδ T cells represent a small subset of T cells that possess a distinct T cell receptor (TCR) on their surface. ... Natural NK cells are cytotoxic; small granules in their cytoplasm contain special proteins such as perforin and proteases known as granzymes. ... A common alternate meaning of virus is computer virus. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... Monocyte A monocyte is a leukocyte, part of the human bodys immune system that protects against blood-borne pathogens and moves quickly (aprox. ... Image File history File links PBMonozyt. ... Image File history File links Monocyte. ... Monocyte A monocyte is a leukocyte, part of the human bodys immune system that protects against blood-borne pathogens and moves quickly (aprox. ... Steps of a macrophage ingesting a pathogen: a. ... A pathogen or infectious agent is a biological agent that causes disease or illness to its host. ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, from makros large + phagein eat) are cells within the tissues that originate from specific white blood cells called monocytes. ... Image File history File linksMetadata Download high resolution version (1280x1024, 279 KB) Summary A macrophage of a mouse stretching itself to eat two smaller particles, possibly pathogens. ... Image File history File links Macrophage. ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, from makros large + phagein eat) are cells within the tissues that originate from specific white blood cells called monocytes. ...

Medications causing leukopenia

Some medications can have an impact on the number and function of white blood cells. Leukopenia is the reduction in the number of white blood cells, which may affect the overall white cell count or one of the specific populations of white blood cells. For example, if the number of neutrophils is low, the condition is known as neutropenia. Likewise, low lymphocyte levels are termed lymphopenia. Medications which can cause leukopenia include clozapine, an antipsychotic medication with a rare adverse effect leading to the total absence of all granulocytes (neutrophils, basophils, eosinophils). Other medications include immunosuppressive drugs, such as sirolimus, mycophenolate mofetil, tacrolimus, and cyclosporine. Interferons used to treat multiple sclerosis, like Rebif, Avonex, and Betaseron, can also cause leukopenia. Leukopenia or leukocytopenia refers to a decrease in the number of circulating white blood cells (leukocytes) in the blood. ... Neutrophil granulocytes (commonly referred to as neutrophils) are a class of white blood cells and are part of the immune system. ... Neutropenia (or neutropaenia, adjective neutrop(a)enic) is a hematological disorder characterized by an abnormally low number of neutrophil granulocytes (a type of white blood cell). ... A scanning electron microscope (SEM) image of a single human lymphocyte. ... Lymphopenia is the condition in which there exists an abnormally low number of lymphocytes in the blood. ... Clozapine (sold as Clozaril®, Leponex®, Fazaclo®) was the first of the atypical antipsychotics to be developed. ... The term antipsychotic is applied to a group of drugs used to treat psychosis. ... Immunosuppression is the medical suppression of the immune system. ... Sirolimus is a relatively new immunosuppressant drug used to prevent rejection in organ transplantation, and is especially useful in kidney transplants. ... Mycophenolate mofetil (MMF, trade name Cellcept®) is an immunosuppresant drug used to prevent rejection in organ transplantation. ... Tacrolimus (also FK-506 or Fujimycin) is an immunosuppressive drug whose main use is after allogenic organ transplant to reduce the activity of the patients immune system and so the risk of organ rejection. ... Cyclosporine (IPA: ), ciclosporin (INN), or cyclosporin (former BAN), is an immunosuppressant drug. ... Interferons (IFNs) are natural proteins produced by the cells of the immune systems of most animals in response to a challenge by a foreign agents such as viruses, bacteria, parasites and tumour cells. ... Interferon beta-1a is a drug in the interferon family used to treat multiple sclerosis. ... Avonex is an interferon drug developed by the Biogen Idec pharmaceutical company for use in the treatment of relapsing/recurring Multiple Sclerosis. ... Betaseron (interferon beta-1B) is a drug used in the treatment of multiple sclerosis. ...


Fixed leukocytes

Some leukocytes migrate into the tissues of the body to take up a permanent residence at that location rather than remaining in the blood. Often these cells have specific names depending upon which tissue they settle in, such as fixed macrophages in the liver which become known as Kupffer cells. These cells still serve a role in the immune system. Kupffer cells or Browicz-Kupffer cells are specialized macrophages located in the liver that form part of the reticuloendothelial system. ...

A Histiocyte is a cell that is part of the human immune system. ... Dendritic cells (DC) are immune cells and form part of the mammal immune system. ... Mast cells A mast cell (or mastocyte) is a resident cell of areolar connective tissue (loose connective tissue) that contains many granules rich in histamine and heparin. ...

Additional image(s)

See also

Leukoreduction is the reduction of white blood cells or leukocytes from the blood or blood components being transfused to the recipient. ... Lymphadenopathy is swelling of one or more lymph nodes. ... Steps of a macrophage ingesting a pathogen: a. ...

References

  1. ^ a b Alberts, Bruce (2005). Leukocyte functions and percentage breakdown. Molecular Biology of the Cell. NCBI Bookshelf. Retrieved on 2007-04-14.

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 14 is the 104th day of the year (105th in leap years) in the Gregorian calendar, with 261 days remaining. ...

External links

A Network Protocol for using leukocytes to ameliorate autoimmune disease is present on the Nature Protocols site: Dorlands Medical Dictionary was first published in 1890 as the American Illustrated Medical Dictionary including 770 pages. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... Nature Protocols Nature Protocols, published by the Nature Publishing Group, is an on-line scientific journal publishing methods in a recipe-style format. ...


  Results from FactBites:
 
White Blood Cell Count (WBC) - Test (517 words)
A white blood cell (WBC) count, also called a leukocyte count, is part of a complete blood count.
WBC counts may vary by as much as 2,000 on any given day, due to strenuous exercise, stress, or digestion.
The WBC count may increase or decrease significantly in certain diseases, but is diagnostically useful only when the patient's white cell differential and clinical status are considered
White blood cell count and differential (751 words)
Cells are identified by the shape and appearance of the nucleus, the color of cytoplasm (the background of the cell), and the presence and color of granules.
White blood cell that increases in response to parasitic infections and allergic reactions.
White blood cell that increases in response to bacterial infection.
  More results at FactBites »

 
 

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