fbpx
Wikipedia

"White blood cells" redirects here. For the album, see White Blood Cells.

White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system.

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.
Details
SystemImmune system
Identifiers
Acronym(s)WBC
MeSHD007962
THH2.00.04.1.02001
FMA62852
Anatomical terms of microanatomy

All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell lineage (myeloid cells or lymphoid cells).

White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes (T cells and B cells).

Myeloid cells (myelocytes) include neutrophils, eosinophils, mast cells, basophils, and monocytes. Monocytes are further subdivided into dendritic cells and macrophages. Monocytes and neutrophils are phagocytic.

Lymphoid cells (lymphocytes) include T cells (subdivided into helper T cells, memory T cells, cytotoxic T cells), B cells (subdivided into plasma cells and memory B cells), and natural killer cells.

Historically, white blood cells were classified by their physical characteristics (granulocytes and agranulocytes), but this classification system is less frequently used now.

Produced in your bone marrow, they defend your body against infections and disease. But, when there are too many white blood cells, it usually means you have infection or inflammation in your body. Less commonly, a high white blood cell count could indicate certain blood cancers or bone marrow disorders.

The number of leukocytes in the blood is often an indicator of disease, and thus the white blood cell count is an important subset of the complete blood count. The normal white cell count is usually between 4 × 109/L and 1.1 × 1010/L. In the US, this is usually expressed as 4,000 to 11,000 white blood cells per microliter of blood. White blood cells make up approximately 1% of the total blood volume in a healthy adult, making them substantially less numerous than the red blood cells at 40% to 45%. However, this 1% of the blood makes a large difference to health, because immunity depends on it. An increase in the number of leukocytes over the upper limits is called leukocytosis. It is normal when it is part of healthy immune responses, which happen frequently. It is occasionally abnormal, when it is neoplastic or autoimmune in origin. A decrease below the lower limit is called leukopenia. This indicates a weakened immune system.

Contents

The name "white blood cell" derives from the physical appearance of a blood sample after centrifugation. White cells are found in the buffy coat, a thin, typically white layer of nucleated cells between the sedimented red blood cells and the blood plasma. The scientific term leukocyte directly reflects its description. It is derived from the Greek roots leuk- meaning "white" and cyt- meaning "cell". The buffy coat may sometimes be green if there are large amounts of neutrophils in the sample, due to the heme-containing enzyme myeloperoxidase that they produce.

Overview

3D rendering of various types of white blood cells

All white blood cells are nucleated, which distinguishes them from the anucleated red blood cells and platelets. Types of leukocytes can be classified in standard ways. Two pairs of broadest categories classify them either by structure (granulocytes or agranulocytes) or by cell lineage (myeloid cells or lymphoid cells). These broadest categories can be further divided into the five main types: neutrophils, eosinophils, basophils, lymphocytes, and monocytes. These types are distinguished by their physical and functional characteristics. Monocytes and neutrophils are phagocytic. Further subtypes can be classified.

Granulocytes are distinguished from agranulocytes by their nucleus shape (lobed versus round, that is, polymorphonuclear versus mononuclear) and by their cytoplasm granules (present or absent, or more precisely, visible on light microscopy or not thus visible). The other dichotomy is by lineage: Myeloid cells (neutrophils, monocytes, eosinophils and basophils) are distinguished from lymphoid cells (lymphocytes) by hematopoietic lineage (cellular differentiation lineage). Lymphocytes can be further classified as T cells, B cells, and natural killer cells.

Type Appearance (micrograph) Appearance (illustration) Approx. %
in adults
See also:
Blood values
Diameter (μm) Main targets Nucleus Granules Lifetime
Neutrophil 62% 10–12 Multilobed Fine, faintly pink (H&E stain) 6 hours–few days
(days in spleen and other tissue)
Eosinophil 2.3% 10–12 Bi-lobed Full of pink-orange (H&E stain) 8–12 days (circulate for 4–5 hours)
Basophil 0.4% 12–15 Bi-lobed or tri-lobed Large blue A few hours to a few days
Lymphocyte 30% Small lymphocytes 7–8

Large lymphocytes 12–15
Deeply staining, eccentric NK-cells and cytotoxic (CD8+) T-cells Years for memory cells, weeks for all else.
Monocyte 5.3% 15–30 Monocytes migrate from the bloodstream to other tissues and differentiate into tissue resident macrophages, Kupffer cells in the liver. Kidney shaped None Hours to days

Neutrophil

Main article: Neutrophil
Neutrophil engulfing anthrax bacteria

Neutrophils are the most abundant white blood cell, constituting 60-70% of the circulating leukocytes. They defend against bacterial or fungal infection. They are usually first responders to microbial infection; their activity and death in large numbers form pus. They are commonly referred to as polymorphonuclear (PMN) leukocytes, although, in the technical sense, PMN refers to all granulocytes. They have a multi-lobed nucleus, which consists of three to five lobes connected by slender strands. This gives the neutrophils the appearance of having multiple nuclei, hence the name polymorphonuclear leukocyte. The cytoplasm may look transparent because of fine granules that are pale lilac when stained. Neutrophils are active in phagocytosing bacteria and are present in large amount in the pus of wounds. These cells are not able to renew their lysosomes (used in digesting microbes) and die after having phagocytosed a few pathogens. Neutrophils are the most common cell type seen in the early stages of acute inflammation. The average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 135 hours.

Eosinophil

Main article: Eosinophil

Eosinophils compose about 2-4% of white blood cells in circulating blood. This count fluctuates throughout the day, seasonally, and during menstruation. It rises in response to allergies, parasitic infections, collagen diseases, and disease of the spleen and central nervous system. They are rare in the blood, but numerous in the mucous membranes of the respiratory, digestive, and lower urinary tracts.

They primarily deal with parasitic infections. 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 parasitic infections. They secrete chemicals that destroy large parasites, such as hookworms and tapeworms, that are too big for any one white blood cell to phagocytize. In general, their nuclei are bi-lobed. The lobes are connected by a thin strand. The cytoplasm is full of granules that assume a characteristic pink-orange color with eosin staining.

Basophil

The movement of leukocytes in the blood. Phase-contrast microscopy.
Main article: Basophil

Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine causing the dilation of blood vessels. Because they are the rarest of the white blood cells (less than 0.5% of the total count) and share physicochemical properties with other blood cells, they are difficult to study. They can be recognized by several coarse, dark violet granules, giving them a blue hue. The nucleus is bi- or tri-lobed, but it is hard to see because of the number of coarse granules that hide it.

They excrete two chemicals that aid in the body's defenses: histamine and heparin. Histamine is responsible for widening blood vessels and increasing the flow of blood to injured tissue. It also makes blood vessels more permeable so neutrophils and clotting proteins can get into connective tissue more easily. Heparin is an anticoagulant that inhibits blood clotting and promotes the movement of white blood cells into an area. Basophils can also release chemical signals that attract eosinophils and neutrophils to an infection site.

Lymphocyte

Main article: Lymphocyte

Lymphocytes are much more common in the lymphatic system than in blood. Lymphocytes are distinguished by having a deeply staining nucleus that may be eccentric in location, and a relatively small amount of cytoplasm. Lymphocytes include:

Monocyte

Main article: Monocyte

Monocytes, the largest type of white blood cell, share the "vacuum cleaner" (phagocytosis) function of neutrophils, but are much longer lived as they have an extra role: they present pieces of pathogens to T cells so that the pathogens may be recognized again and killed. This causes an antibody response to be mounted. Monocytes eventually leave the bloodstream and become tissue macrophages, which remove dead cell debris as well as attack microorganisms. Neither dead cell debris nor attacking microorganisms can be dealt with effectively by the neutrophils. Unlike neutrophils, monocytes are able to replace their lysosomal contents and are thought to have a much longer active life. They have the kidney-shaped nucleus and are typically not granulated. They also possess abundant cytoplasm.

Some leucocytes 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.

The two commonly used categories of white blood cell disorders divide them quantitatively into those causing excessive numbers (proliferative disorders) and those causing insufficient numbers (leukopenias). Leukocytosis is usually healthy (e.g., fighting an infection), but it also may be dysfunctionally proliferative. Proliferative disorders of white blood cells can be classed as myeloproliferative and lymphoproliferative. Some are autoimmune, but many are neoplastic.

Another way to categorize disorders of white blood cells is qualitatively. There are various disorders in which the number of white blood cells is normal but the cells do not function normally.

Neoplasia of white blood cells can be benign but is often malignant. Of the various tumors of the blood and lymph, cancers of white blood cells can be broadly classified as leukemias and lymphomas, although those categories overlap and are often grouped together.

Leucopenias

Main article: Leucopenia

A range of disorders can cause decreases in white blood cells. This type of white blood cell decreased is usually the neutrophil. In this case the decrease may be called neutropenia or granulocytopenia. Less commonly, a decrease in lymphocytes (called lymphocytopenia or lymphopenia) may be seen.

Neutropenia

Main article: Neutropenia

Neutropenia can be acquired or intrinsic. A decrease in levels of neutrophils on lab tests is due to either decreased production of neutrophils or increased removal from the blood. The following list of causes is not complete.

Symptoms of neutropenia are associated with the underlying cause of the decrease in neutrophils. For example, the most common cause of acquired neutropenia is drug-induced, so an individual may have symptoms of medication overdose or toxicity. Treatment is also aimed at the underlying cause of the neutropenia. One severe consequence of neutropenia is that it can increase the risk of infection.

Lymphocytopenia

Main article: Lymphocytopenia

Defined as total lymphocyte count below 1.0x109/L, the cells most commonly affected are CD4+ T cells. Like neutropenia, lymphocytopenia may be acquired or intrinsic and there are many causes. This is not a complete list.

Like neutropenia, symptoms and treatment of lymphocytopenia are directed at the underlying cause of the change in cell counts.

Proliferative disorders

Main article: Leukocytosis

An increase in the number of white blood cells in circulation is called leukocytosis. This increase is most commonly caused by inflammation. There are four major causes: increase of production in bone marrow, increased release from storage in bone marrow, decreased attachment to veins and arteries, decreased uptake by tissues. Leukocytosis may affect one or more cell lines and can be neutrophilic, eosinophilic, basophilic, monocytosis, or lymphocytosis.

Neutrophilia

Main article: Neutrophilia

Neutrophilia is an increase in the absolute neutrophil count in the peripheral circulation. Normal blood values vary by age. Neutrophilia can be caused by a direct problem with blood cells (primary disease). It can also occur as a consequence of an underlying disease (secondary). Most cases of neutrophilia are secondary to inflammation.

Primary causes

Secondary causes

Eosinophilia

Main article: Eosinophilia

A normal eosinophil count is considered to be less than 0.65×109/L. Eosinophil counts are higher in newborns and vary with age, time (lower in the morning and higher at night), exercise, environment, and exposure to allergens. Eosinophilia is never a normal lab finding. Efforts should always be made to discover the underlying cause, though the cause may not always be found.

The complete blood cell count is a blood panel that includes the overall white blood cell count and differential count, a count of each type of white blood cell. Reference ranges for blood tests specify the typical counts in healthy people.

The normal total leucocyte count in an adult is 4000 to 11,000 per mm3 of blood.

Differential leucocyte count: number/ (%) of different types of leucocytes per cubic mm. of blood. Below are reference ranges for various types leucocytes.

  1. Monga I, Kaur K, Dhanda S (March 2022). "Revisiting hematopoiesis: applications of the bulk and single-cell transcriptomics dissecting transcriptional heterogeneity in hematopoietic stem cells". Briefings in Functional Genomics. 21 (3): 159–176. doi:10.1093/bfgp/elac002. PMID 35265979.
  2. Maton D, Hopkins J, McLaughlin CW, Johnson S, Warner MQ, LaHart D, Wright JD, Kulkarni DV (1997). Human Biology and Health. Englewood Cliffs, New Jersey, US: Prentice Hall. ISBN 0-13-981176-1.
  3. www.cancer.gov. 2 February 2011 https://www.cancer.gov/publications/dictionaries/cancer-terms/def/white-blood-cell. Retrieved3 June 2022.{{cite web}}:Missing or empty |title= ()
  4. LaFleur-Brooks M (2008). Exploring Medical Language: A Student-Directed Approach (7th ed.). St. Louis, Missouri, US: Mosby Elsevier. p. 398. ISBN 978-0-323-04950-4.
  5. "Vital and Health Statistics Series 11, No. 247 (03/2005)"(PDF). Retrieved2 February 2014.
  6. Alberts B, Johnson A, Lewis M, Raff M, Roberts K, Walter P (2002). "Leukocyte also known as macrophagesfunctions and percentage breakdown". Molecular Biology of the Cell (4th ed.). New York: Garland Science. ISBN 0-8153-4072-9.
  7. "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine. 1 (2). 2014. doi:10.15347/wjm/2014.010.
  8. Orkin SH, Zon LI (February 2008). "SnapShot: hematopoiesis". Cell. 132 (4): 712.e1–712.e2. doi:10.1016/j.cell.2008.02.013. PMID 18295585. S2CID 26791665.
  9. Daniels VG, Wheater PR, Burkitt HG (1979). Functional histology: A text and colour atlas. Edinburgh: Churchill Livingstone. ISBN 0-443-01657-7.
  10. Handin RI, Lux SE, Stossel TP (2003). Blood: Principles and Practice of Hematology (2nd ed.). Philadelphia: Lippincott Williams and Wilkins. p. 471. ISBN 9780781719933. Retrieved18 June 2013.
  11. Saladin K (2012). Anatomy and Physiology: the Unit of Form and Function (6 ed.). New York: McGraw Hill. ISBN 978-0-07-337825-1.
  12. Wheater PR, Stevens A (2002). Wheater's basic histopathology: a colour atlas and text(PDF). Edinburgh: Churchill Livingstone. ISBN 0-443-07001-6.
  13. Tak T, Tesselaar K, Pillay J, Borghans JA, Koenderman L (October 2013). "What's your age again? Determination of human neutrophil half-lives revisited". Journal of Leukocyte Biology. 94 (4): 595–601. doi:10.1189/jlb.1112571. PMID 23625199. S2CID 40113921.
  14. Pillay J, den Braber I, Vrisekoop N, Kwast LM, de Boer RJ, Borghans JA, Tesselaar K, Koenderman L (July 2010). "In vivo labeling with 2H2O reveals a human neutrophil lifespan of 5.4 days". Blood. 116 (4): 625–7. doi:10.1182/blood-2010-01-259028. PMID 20410504.
  15. Falcone FH, Haas H, Gibbs BF (December 2000). "The human basophil: a new appreciation of its role in immune responses". Blood. 96 (13): 4028–38. doi:10.1182/blood.V96.13.4028. PMID 11110670.
  16. Kumar V, et al. (2010). Robbins and Cotran pathologic basis of disease (8th ed.). Philadelphia, PA: Saunders/Elsevier. ISBN 978-1416031215.
  17. Kaushansky K, et al., eds. (2010). Williams hematology (8th ed.). New York: McGraw-Hill Medical. ISBN 978-0-07-162151-9.
  18. McPherson RA, Pincus MR, Abraham NZ, et al., eds. (2011). Henry's clinical diagnosis and management by laboratory methods (22nd ed.). Philadelphia, PA: Elsevier/Saunders. ISBN 978-1437709742.
  19. Goldman L, Schafer AI, eds. (January 2012). Goldman's Cecil medicine (24th ed.). Philadelphia: Elsevier/Saunders. ISBN 978-1437716047.
  20. McBride JA, Dacie JV, Shapley R (February 1968). "The effect of splenectomy on the leucocyte count". British Journal of Haematology. 14 (2): 225–31. doi:10.1111/j.1365-2141.1968.tb01489.x. PMID 5635603. S2CID 45703201.
  21. Specific references are found in article Reference ranges for blood tests#White blood cells 2.
Wikimedia Commons has media related toLeukocytes.

White blood cell Article Talk Language Watch Edit White blood cells redirects here For the album see White Blood Cells White blood cells also called leukocytes or leucocytes are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells 1 Leukocytes are found throughout the body including the blood and lymphatic system 2 White blood cellA 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 DetailsSystemImmune systemIdentifiersAcronym s WBCMeSHD007962THH2 00 04 1 02001FMA62852Anatomical terms of microanatomy edit on Wikidata All white blood cells have nuclei which distinguishes them from the other blood cells the anucleated red blood cells RBCs and platelets The different white blood cells are usually classified by cell lineage myeloid cells or lymphoid cells White blood cells are part of the body s immune system They help the body fight infection and other diseases Types of white blood cells are granulocytes neutrophils eosinophils and basophils monocytes and lymphocytes T cells and B cells 3 Myeloid cells myelocytes include neutrophils eosinophils mast cells basophils and monocytes 4 Monocytes are further subdivided into dendritic cells and macrophages Monocytes and neutrophils are phagocytic Lymphoid cells lymphocytes include T cells subdivided into helper T cells memory T cells cytotoxic T cells B cells subdivided into plasma cells and memory B cells and natural killer cells Historically white blood cells were classified by their physical characteristics granulocytes and agranulocytes but this classification system is less frequently used now Produced in your bone marrow they defend your body against infections and disease But when there are too many white blood cells it usually means you have infection or inflammation in your body Less commonly a high white blood cell count could indicate certain blood cancers or bone marrow disorders The number of leukocytes in the blood is often an indicator of disease and thus the white blood cell count is an important subset of the complete blood count The normal white cell count is usually between 4 109 L and 1 1 1010 L In the US this is usually expressed as 4 000 to 11 000 white blood cells per microliter of blood 5 White blood cells make up approximately 1 of the total blood volume in a healthy adult 6 making them substantially less numerous than the red blood cells at 40 to 45 However this 1 of the blood makes a large difference to health because immunity depends on it An increase in the number of leukocytes over the upper limits is called leukocytosis It is normal when it is part of healthy immune responses which happen frequently It is occasionally abnormal when it is neoplastic or autoimmune in origin A decrease below the lower limit is called leukopenia This indicates a weakened immune system Contents 1 Etymology 2 Types 2 1 Overview 2 2 Neutrophil 2 3 Eosinophil 2 4 Basophil 2 5 Lymphocyte 2 6 Monocyte 3 Fixed leucocytes 4 Disorders 4 1 Leucopenias 4 1 1 Neutropenia 4 1 2 Lymphocytopenia 4 2 Proliferative disorders 4 2 1 Neutrophilia 4 2 2 Eosinophilia 5 Counting and reference ranges 6 See also 7 References 8 External linksEtymology EditThe name white blood cell derives from the physical appearance of a blood sample after centrifugation White cells are found in the buffy coat a thin typically white layer of nucleated cells between the sedimented red blood cells and the blood plasma The scientific term leukocyte directly reflects its description It is derived from the Greek roots leuk meaning white and cyt meaning cell The buffy coat may sometimes be green if there are large amounts of neutrophils in the sample due to the heme containing enzyme myeloperoxidase that they produce Types EditOverview Edit 3D rendering of various types of white blood cells 7 All white blood cells are nucleated which distinguishes them from the anucleated red blood cells and platelets Types of leukocytes can be classified in standard ways Two pairs of broadest categories classify them either by structure granulocytes or agranulocytes or by cell lineage myeloid cells or lymphoid cells These broadest categories can be further divided into the five main types neutrophils eosinophils basophils lymphocytes and monocytes 4 These types are distinguished by their physical and functional characteristics Monocytes and neutrophils are phagocytic Further subtypes can be classified Granulocytes are distinguished from agranulocytes by their nucleus shape lobed versus round that is polymorphonuclear versus mononuclear and by their cytoplasm granules present or absent or more precisely visible on light microscopy or not thus visible The other dichotomy is by lineage Myeloid cells neutrophils monocytes eosinophils and basophils are distinguished from lymphoid cells lymphocytes by hematopoietic lineage cellular differentiation lineage 8 Lymphocytes can be further classified as T cells B cells and natural killer cells Type Appearance micrograph Appearance illustration Approx in adults See also Blood values Diameter mm 9 Main targets 6 Nucleus 6 Granules 6 Lifetime 9 Neutrophil 62 10 12 Bacteria Fungi Multilobed Fine faintly pink H amp E stain 6 hours few days days in spleen and other tissue Eosinophil 2 3 10 12 Larger parasites Modulate allergic inflammatory responses Bi lobed Full of pink orange H amp E stain 8 12 days circulate for 4 5 hours Basophil 0 4 12 15 Release histamine for inflammatory responses Bi lobed or tri lobed Large blue A few hours to a few daysLymphocyte 30 Small lymphocytes 7 8 Large lymphocytes 12 15 B cells releases antibodies and assists activation of T cells T cells CD4 Th T helper cells activate and regulate T and B cells CD8 cytotoxic T cells virus infected and tumor cells Gamma delta T cells bridge between innate and adaptive immune responses phagocytosis Regulatory suppressor T cells Returns the functioning of the immune system to normal operation after infection prevents autoimmunity Natural killer cells virus infected and tumor cells Deeply staining eccentric NK cells and cytotoxic CD8 T cells Years for memory cells weeks for all else Monocyte 5 3 15 30 10 Monocytes migrate from the bloodstream to other tissues and differentiate into tissue resident macrophages Kupffer cells in the liver Kidney shaped None Hours to daysNeutrophil Edit Main article Neutrophil Neutrophil engulfing anthrax bacteria Neutrophils are the most abundant white blood cell constituting 60 70 of the circulating leukocytes 6 They defend against bacterial or fungal infection They are usually first responders to microbial infection their activity and death in large numbers form pus They are commonly referred to as polymorphonuclear PMN leukocytes although in the technical sense PMN refers to all granulocytes They have a multi lobed nucleus which consists of three to five lobes connected by slender strands 11 This gives the neutrophils the appearance of having multiple nuclei hence the name polymorphonuclear leukocyte The cytoplasm may look transparent because of fine granules that are pale lilac when stained Neutrophils are active in phagocytosing bacteria and are present in large amount in the pus of wounds These cells are not able to renew their lysosomes used in digesting microbes and die after having phagocytosed a few pathogens 12 Neutrophils are the most common cell type seen in the early stages of acute inflammation The average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 135 hours 13 14 Eosinophil Edit Main article Eosinophil Eosinophils compose about 2 4 of white blood cells in circulating blood This count fluctuates throughout the day seasonally and during menstruation It rises in response to allergies parasitic infections collagen diseases and disease of the spleen and central nervous system They are rare in the blood but numerous in the mucous membranes of the respiratory digestive and lower urinary tracts 11 They primarily deal with parasitic infections 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 parasitic infections They secrete chemicals that destroy large parasites such as hookworms and tapeworms that are too big for any one white blood cell to phagocytize In general their nuclei are bi lobed The lobes are connected by a thin strand 11 The cytoplasm is full of granules that assume a characteristic pink orange color with eosin staining Basophil Edit source source source source source source source source source source source source source source The movement of leukocytes in the blood Phase contrast microscopy Main article Basophil Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine causing the dilation of blood vessels Because they are the rarest of the white blood cells less than 0 5 of the total count and share physicochemical properties with other blood cells they are difficult to study 15 They can be recognized by several coarse dark violet granules giving them a blue hue The nucleus is bi or tri lobed but it is hard to see because of the number of coarse granules that hide it They excrete two chemicals that aid in the body s defenses histamine and heparin Histamine is responsible for widening blood vessels and increasing the flow of blood to injured tissue It also makes blood vessels more permeable so neutrophils and clotting proteins can get into connective tissue more easily Heparin is an anticoagulant that inhibits blood clotting and promotes the movement of white blood cells into an area Basophils can also release chemical signals that attract eosinophils and neutrophils to an infection site 11 Lymphocyte Edit Main article Lymphocyte Lymphocytes are much more common in the lymphatic system than in blood Lymphocytes are distinguished by having a deeply staining nucleus that may be eccentric in location and a relatively small amount of cytoplasm Lymphocytes include B cells make antibodies that can bind to pathogens block pathogen invasion activate the complement system and enhance pathogen destruction T cells CD4 helper T cells T cells displaying co receptor CD4 are known as CD4 T cells These cells have T cell receptors and CD4 molecules that in combination bind antigenic peptides presented on major histocompatibility complex MHC class II molecules on antigen presenting cells Helper T cells make cytokines and perform other functions that help coordinate the immune response In HIV infection these T cells are the main index to identify the individual s immune system integrity CD8 cytotoxic T cells T cells displaying co receptor CD8 are known as CD8 T cells These cells bind antigens presented on MHC I complex of virus infected or tumour cells and kill them Nearly all nucleated cells display MHC I gd T cells possess an alternative T cell receptor different from the ab TCR found on conventional CD4 and CD8 T cells Found in tissue more commonly than in blood gd T cells share characteristics of helper T cells cytotoxic T cells and natural killer cells Natural killer cells are able to kill cells of the body that do not display MHC class I molecules or display stress markers such as MHC class I polypeptide related sequence A MIC A Decreased expression of MHC class I and up regulation of MIC A can happen when cells are infected by a virus or become cancerous Monocyte Edit Main article Monocyte Monocytes the largest type of white blood cell share the vacuum cleaner phagocytosis function of neutrophils but are much longer lived as they have an extra role they present pieces of pathogens to T cells so that the pathogens may be recognized again and killed This causes an antibody response to be mounted Monocytes eventually leave the bloodstream and become tissue macrophages which remove dead cell debris as well as attack microorganisms Neither dead cell debris nor attacking microorganisms can be dealt with effectively by the neutrophils Unlike neutrophils monocytes are able to replace their lysosomal contents and are thought to have a much longer active life They have the kidney shaped nucleus and are typically not granulated They also possess abundant cytoplasm Fixed leucocytes Edit HSC Hematopoietic stem cell Progenitor Progenitor cell L blast Lymphoblast Lymphocyte Mo blast Monoblast Monocyte Myeloblast Pro M Promyelocyte Myelocyte Meta M Metamyelocyte Neutrophil Eosinophil Basophil Pro E Proerythroblast Baso E Basophilic erythroblast poly E Polychromatic erythroblast Ortho E Orthochromatic erythroblast Erythrocyte Promegakaryocyte Megakaryocyte Platelet Some leucocytes 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 Histiocytes Dendritic cells Although these will often migrate to local lymph nodes upon ingesting antigens Mast cells MicrogliaDisorders EditThe two commonly used categories of white blood cell disorders divide them quantitatively into those causing excessive numbers proliferative disorders and those causing insufficient numbers leukopenias 16 Leukocytosis is usually healthy e g fighting an infection but it also may be dysfunctionally proliferative Proliferative disorders of white blood cells can be classed as myeloproliferative and lymphoproliferative Some are autoimmune but many are neoplastic Another way to categorize disorders of white blood cells is qualitatively There are various disorders in which the number of white blood cells is normal but the cells do not function normally 17 Neoplasia of white blood cells can be benign but is often malignant Of the various tumors of the blood and lymph cancers of white blood cells can be broadly classified as leukemias and lymphomas although those categories overlap and are often grouped together Leucopenias Edit Main article Leucopenia A range of disorders can cause decreases in white blood cells This type of white blood cell decreased is usually the neutrophil In this case the decrease may be called neutropenia or granulocytopenia Less commonly a decrease in lymphocytes called lymphocytopenia or lymphopenia may be seen 16 Neutropenia Edit Main article Neutropenia Neutropenia can be acquired or intrinsic 18 A decrease in levels of neutrophils on lab tests is due to either decreased production of neutrophils or increased removal from the blood 16 The following list of causes is not complete Medications chemotherapy sulfas or other antibiotics phenothiazines benzodiazepines antithyroid medications anticonvulsants quinine quinidine indomethacin procainamide thiazides Radiation Toxins alcohol benzenes Intrinsic disorders Fanconi s Kostmann s cyclic neutropenia Chediak Higashi Immune dysfunction disorders of collagen AIDS rheumatoid arthritis Blood cell dysfunction megaloblastic anemia myelodysplasia marrow failure marrow replacement acute leukemia Any major infection Miscellaneous starvation hypersplenism Symptoms of neutropenia are associated with the underlying cause of the decrease in neutrophils For example the most common cause of acquired neutropenia is drug induced so an individual may have symptoms of medication overdose or toxicity Treatment is also aimed at the underlying cause of the neutropenia 19 One severe consequence of neutropenia is that it can increase the risk of infection 17 Lymphocytopenia Edit Main article Lymphocytopenia Defined as total lymphocyte count below 1 0x109 L the cells most commonly affected are CD4 T cells Like neutropenia lymphocytopenia may be acquired or intrinsic and there are many causes 17 This is not a complete list Inherited immune deficiency severe combined immunodeficiency common variable immune deficiency ataxia telangiectasia Wiskott Aldrich syndrome immunodeficiency with short limbed dwarfism immunodeficiency with thymoma purine nucleoside phosphorylase deficiency genetic polymorphism Blood cell dysfunction aplastic anemia Infectious diseases viral AIDS SARS West Nile encephalitis hepatitis herpes measles others bacterial TB typhoid pneumonia rickettsiosis ehrlichiosis sepsis parasitic acute phase of malaria Medications chemotherapy antilymphocyte globulin therapy alemtuzumab glucocorticoids Radiation Major surgery Miscellaneous ECMO kidney or bone marrow transplant hemodialysis kidney failure severe burns celiac disease severe acute pancreatitis sarcoidosis protein losing enteropathy strenuous exercise carcinoma Immune dysfunction arthritis systemic lupus erythematosus Sjogren syndrome myasthenia gravis systemic vasculitis Behcet like syndrome dermatomyositis granulomatosis with polyangiitis Nutritional Dietary alcohol use disorder zinc deficiency Like neutropenia symptoms and treatment of lymphocytopenia are directed at the underlying cause of the change in cell counts Proliferative disorders Edit Main article Leukocytosis An increase in the number of white blood cells in circulation is called leukocytosis 16 This increase is most commonly caused by inflammation 16 There are four major causes increase of production in bone marrow increased release from storage in bone marrow decreased attachment to veins and arteries decreased uptake by tissues 16 Leukocytosis may affect one or more cell lines and can be neutrophilic eosinophilic basophilic monocytosis or lymphocytosis Neutrophilia Edit Main article Neutrophilia Neutrophilia is an increase in the absolute neutrophil count in the peripheral circulation Normal blood values vary by age 17 Neutrophilia can be caused by a direct problem with blood cells primary disease It can also occur as a consequence of an underlying disease secondary Most cases of neutrophilia are secondary to inflammation 19 Primary causes 19 Conditions with normally functioning neutrophils hereditary neutrophilia chronic idiopathic neutrophilia Pelger Huet anomaly Down syndrome Leukocyte adhesion deficiency Familial cold urticaria Leukemia chronic myelogenous CML and other myeloproliferative disorders Surgical removal of spleen 20 Secondary causes 19 Infection Chronic inflammation especially juvenile rheumatoid arthritis rheumatoid arthritis Still s disease Crohn s disease ulcerative colitis granulomatous infections for example tuberculosis and chronic hepatitis Cigarette smoking occurs in 25 50 of chronic smokers and can last up to 5 years after quitting Stress exercise surgery general stress Medication induced corticosteroids for example prednisone b agonists lithium Cancer either by growth factors secreted by the tumor or invasion of bone marrow by the cancer Increased destruction of cells in peripheral circulation can stimulate bone marrow This can occur in hemolytic anemia and idiopathic thrombocytopenic purpuraEosinophilia Edit Main article Eosinophilia A normal eosinophil count is considered to be less than 0 65 109 L 17 Eosinophil counts are higher in newborns and vary with age time lower in the morning and higher at night exercise environment and exposure to allergens 17 Eosinophilia is never a normal lab finding Efforts should always be made to discover the underlying cause though the cause may not always be found 17 Counting and reference ranges EditMain article White blood cell differential The complete blood cell count is a blood panel that includes the overall white blood cell count and differential count a count of each type of white blood cell Reference ranges for blood tests specify the typical counts in healthy people The normal total leucocyte count in an adult is 4000 to 11 000 per mm3 of blood Differential leucocyte count number of different types of leucocytes per cubic mm of blood Below are reference ranges for various types leucocytes 21 See also EditLeukocyte promoting factorPortals Biology MedicineReferences Edit Monga I Kaur K Dhanda S March 2022 Revisiting hematopoiesis applications of the bulk and single cell transcriptomics dissecting transcriptional heterogeneity in hematopoietic stem cells Briefings in Functional Genomics 21 3 159 176 doi 10 1093 bfgp elac002 PMID 35265979 Maton D Hopkins J McLaughlin CW Johnson S Warner MQ LaHart D Wright JD Kulkarni DV 1997 Human Biology and Health Englewood Cliffs New Jersey US Prentice Hall ISBN 0 13 981176 1 www cancer gov 2 February 2011 https www cancer gov publications dictionaries cancer terms def white blood cell Retrieved 3 June 2022 a href wiki Template Cite web title Template Cite web cite web a Missing or empty title help a b LaFleur Brooks M 2008 Exploring Medical Language A Student Directed Approach 7th ed St Louis Missouri US Mosby Elsevier p 398 ISBN 978 0 323 04950 4 Vital and Health Statistics Series 11 No 247 03 2005 PDF Retrieved 2 February 2014 a b c d e Alberts B Johnson A Lewis M Raff M Roberts K Walter P 2002 Leukocyte also known as macrophagesfunctions and percentage breakdown Molecular Biology of the Cell 4th ed New York Garland Science ISBN 0 8153 4072 9 Medical gallery of Blausen Medical 2014 WikiJournal of Medicine 1 2 2014 doi 10 15347 wjm 2014 010 Orkin SH Zon LI February 2008 SnapShot hematopoiesis Cell 132 4 712 e1 712 e2 doi 10 1016 j cell 2008 02 013 PMID 18295585 S2CID 26791665 a b Daniels VG Wheater PR Burkitt HG 1979 Functional histology A text and colour atlas Edinburgh Churchill Livingstone ISBN 0 443 01657 7 Handin RI Lux SE Stossel TP 2003 Blood Principles and Practice of Hematology 2nd ed Philadelphia Lippincott Williams and Wilkins p 471 ISBN 9780781719933 Retrieved 18 June 2013 a b c d Saladin K 2012 Anatomy and Physiology the Unit of Form and Function 6 ed New York McGraw Hill ISBN 978 0 07 337825 1 Wheater PR Stevens A 2002 Wheater s basic histopathology a colour atlas and text PDF Edinburgh Churchill Livingstone ISBN 0 443 07001 6 Tak T Tesselaar K Pillay J Borghans JA Koenderman L October 2013 What s your age again Determination of human neutrophil half lives revisited Journal of Leukocyte Biology 94 4 595 601 doi 10 1189 jlb 1112571 PMID 23625199 S2CID 40113921 Pillay J den Braber I Vrisekoop N Kwast LM de Boer RJ Borghans JA Tesselaar K Koenderman L July 2010 In vivo labeling with 2H2O reveals a human neutrophil lifespan of 5 4 days Blood 116 4 625 7 doi 10 1182 blood 2010 01 259028 PMID 20410504 Falcone FH Haas H Gibbs BF December 2000 The human basophil a new appreciation of its role in immune responses Blood 96 13 4028 38 doi 10 1182 blood V96 13 4028 PMID 11110670 a b c d e f Kumar V et al 2010 Robbins and Cotran pathologic basis of disease 8th ed Philadelphia PA Saunders Elsevier ISBN 978 1416031215 a b c d e f g Kaushansky K et al eds 2010 Williams hematology 8th ed New York McGraw Hill Medical ISBN 978 0 07 162151 9 McPherson RA Pincus MR Abraham NZ et al eds 2011 Henry s clinical diagnosis and management by laboratory methods 22nd ed Philadelphia PA Elsevier Saunders ISBN 978 1437709742 a b c d Goldman L Schafer AI eds January 2012 Goldman s Cecil medicine 24th ed Philadelphia Elsevier Saunders ISBN 978 1437716047 McBride JA Dacie JV Shapley R February 1968 The effect of splenectomy on the leucocyte count British Journal of Haematology 14 2 225 31 doi 10 1111 j 1365 2141 1968 tb01489 x PMID 5635603 S2CID 45703201 Specific references are found in article Reference ranges for blood tests White blood cells 2 External links EditWikimedia Commons has media related to Leukocytes Atlas of Hematology Leukocytes at the US National Library of Medicine Medical Subject Headings MeSH Retrieved from https en wikipedia org w index php title White blood cell amp oldid 1093684493, wikipedia, wiki, book,

books

, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.