خلية دم بيضاء

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

خلايا الدم البيضاء White Blood Cells تدعى أيضًا بالخلايا البيض Leukocytes وتكافح الالتهابات والمواد المؤذية التي تهاجم الجسم. معظم هذه الخلايا مستديرة وعديمة اللون ولها أحجام عديدة وتختلف أشكال نواها. تقتل بعض أنواع الكريات البيض البكتيريا وذلك بالإحاطة بها وهضمها. تنتج أنواع أخرى منها الأجسام المضادة التي هي بروتينات تقضي على البكتيريا والفيروسات ومغيرات أخرى، أو تجعلها عديمة الأذى. هناك خمسة طرز من خلايا الدم البيضاء، وهي تصنف في مجموعتين على أساس حبيبات السيتوبلازم بها ، وعلى حسب شكل النواة.

The functions and morphology of these cells are as follows:[1]

النوع صورة رسم تفصيلي ~% في البشر الوصف
خلية محببة متعادلة Neutrophil PBNeutrophil.jpg Neutrophil.png 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.
خلية محببة إيوسينية Eosinophil Eosinophil.jpg Eosinophil2.png 4% Eosinophils primarily deal with parasitic infections and an increase in them may indicate such.
خلية محببة قاعدة Basophil PBBasophil.jpg Basophil.png <1% Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine causing inflammation.
خلية ليمفية Lymphocyte Lymphocyte2.jpg Lymphocyte.png 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.
وحيدة Monocyte PBMonozyt.jpg Monocyte.png 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.
بالعة Macrophage Macrophage.jpg Macrophage.png (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.

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  1. ^ خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة alberts_table

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