WBCs Structures and Function
WBCsStructures and Function
Underthis class, there are three types of cells namely eosinophils,basophils, and neutrophils (Ball, 2015).
Asseen under a microscope, these cells possess a single nucleusconsisting of multiple lobes (Ball, 2015). They are attracted bypathogens through chemical signals and migrate to the sites ofinfection (Ball, 2015). They destroy target cells throughphagocytosis.
Thenucleus of this group of cells has a U-shape and appears to bedouble-lobed in blood smears (Ball, 2015). They destroy target cellsthrough the process of phagocytosis, and their primary targets areantigen-antibody complexes (Ball, 2015). They are mostly activeduring allergic reactions and parasitic infections.
Theyare the least numerous cells. They have multi-lobed nuclei, and theirgranules possess heparin and histamine (Ball, 2015). Heparin helps inthinning blood while histamine increases the permeability ofcapillaries, and dilates blood vessels (Ball, 2015). They are mainlyresponsible for allergic reactions.
Theyinclude monocytes and lymphocytes. Under a microscope, they appear tohave no granules (Ball, 2015).
Theyhave a spherical shape with a petite cytoplasm and a large nucleus(Ball, 2015). There are three main subtypes of lymphocytes namely Bcells, T cells, and natural killer cells (Ball, 2015). The B cellsand T cells are vital in specific immune responses while naturalkiller cells offer non-specific immunity (Ball, 2015).
Theypossess a single nucleus that can be of various shapes (Ball, 2015).The most common shape is the kidney shape. These cells migrate fromthe blood into various tissues where they mature into dendritic cellsand macrophages (Ball, 2015). Macrophages offer protection throughphagocytosis while dendritic cells present antigenic formations tolymphocytes in the lymph organs and lymph nodes (Ball, 2015).
TheCommon Types of Excessive and Deficiencies of White Blood Cells
Thestandard count range is 4000 – 11000 cells per microliter (Ball,2015). An abnormal increase or decrease in the number of these cellsmay indicate the presence of a disorder. They include:
Thisdisorder represents a reduction in the number of WBCs in the bloodbelow the normal 4000 cells per a microliter of blood (Ball, 2015).Under this category, there can be neutropenia (decrease ofneutrophils) and lymphocytopenia (decrease of lymphocytes).
Thisdisorder represents an increase in the number of WBCs in the bloodabove the normal 11000 cells per a microliter of blood (Ball, 2015).The increase is mainly due to inflammation. Types of leukocytosisinclude neutrophilia and eosinophilia.
Ball,L. A. (2015). Studyguide for introduction to human anatomy and physiology.Saunders.
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