Granulocytes are a category of white blood cells characterised by the presence of granules in their cytoplasm. In cell biology, a granule can be any structure barely visible by light microscopy The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. [1] They are also called polymorphonuclear leukocytes (PMN or PML) because of the varying shapes of the nucleus, which is usually lobed into three segments. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed In common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil granulocytes,[2] the most abundant of the granulocytes. Neutrophil granulocytes, generally referred to as neutrophils, are the most abundant type of White blood cells in humans and form an essential part of the Granulocytes or PMN are released from the bone marrow by the regulatory complement proteins. The complement system is a Biochemical cascade that helps clear Pathogens from an organism
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Classification
There are three types of granulocytes, distinguished by their appearance under Wright's stain:
- Neutrophil granulocytes
- Eosinophil granulocytes
- Basophil granulocytes. Wright's stain is a Histologic stain that facilitates the differentiation of Blood cell types Neutrophil granulocytes, generally referred to as neutrophils, are the most abundant type of White blood cells in humans and form an essential part of the Eosinophil granulocytes, usually called eosinophils (or less commonly acidophils) are White blood cells that are one of the Immune System components
Their names are derived from their staining characteristics; for example, the most abundant granulocyte is the neutrophil granulocyte, which has neutrally-staining cytoplasmic granules. Staining is an auxiliary Technique used in Microscopy to enhance contrast in the microscopic image Neutrophil granulocytes, generally referred to as neutrophils, are the most abundant type of White blood cells in humans and form an essential part of the The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane.
Other white blood cells which are not granulocytes ("agranulocytes") are mainly lymphocytes and monocytes. Agranulocytes are a category of White blood cells characterised by the absence of granules in their Cytoplasm. A lymphocyte is a type of White blood cell in the Vertebrate Immune system. Monocyte is a type of Leukocyte, part of the Human body 's Immune system.
Toxic materials produced or released
Examples of toxic materials produced or released by degranulation by granulocytes on the ingestion of microorganism includes:
- Low pH vesicles (3. Degranulation is a cellular process that releases Antimicrobial Cytotoxic molecules from secretory vesicles called granules found inside A vesicle is a small bubble of liquid within a cell A more formal definition in Cell biology, would be that a vesicle is a relatively small intracellular membrane-enclosed 5-4. 0)
- Toxic oxygen-derived products (e. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the g. superoxide, hydrogen peroxide, hydroxy radicals, singlet oxygen, hypohalite)
- Toxic nitrogen oxides (nitric oxide)
- Antimicrobial agents (Defensins and cationic proteins)
- Enzymes
- Lysozyme: dissolves cell walls of some gram positive bacteria
- Acid hydrolases: further digest bacteria
Pathology
Granulocytopenia is an abnormally low concentration of granulocytes in the blood. Superoxide is the Anion O2&minus It is important as the product of the one-electron reduction of Dioxygen, which occurs widely in nature Hydrogen peroxide (H2O2 is a very pale blue liquid which appears colorless in a dilute solution slightly more Viscous than water The hypochlorite Ion is Cl[[Oxygen O]]− A hypochlorite compound is a Chemical compound containing this group with chlorine in Oxidation Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Nitric oxide or nitrogen monoxide is a Chemical compound with Chemical formula N[[Oxygen O]] An antimicrobial is a substance that kills or inhibits the growth of Microbes such as Bacteria, Fungi, or Viruses. Defensins are small (15-20 residue) Cysteine -rich Cationic Proteins found in both Vertebrates and Invertebrates They are An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Lysozyme is a family of Enzymes ( which damage bacterial cell walls by catalyzing Hydrolysis of 14-beta-linkages between N-acetylmuramic acid and Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. An acid hydrolase ( Lysosomal Acid Lipase) is an Enzyme that works best at acidic PHs It is commonly located in Lysosomes This condition reduces the body's resistance to many infections. Closely-related terms include agranulocytosis (no granulocytes at all) and neutropenia (deficiency of neutrophil granulocytes). Agranulocytosis is an acute condition involving a severe and dangerous Leukopenia particularly of neutrophils causing a Neutropenia in the circulating blood Neutropenia (adjective neutropenic) from Latin Prefix neutro- and Greek Suffix -πενία (deficiency is Neutrophil granulocytes, generally referred to as neutrophils, are the most abundant type of White blood cells in humans and form an essential part of the Transfusion of granulocytes would have been a solution to the problem. Blood transfusion is the process of transferring Blood or blood-based products from one person into the Circulatory system of another However, granulocytes live only ~10 hours in the circulation (for days in spleen or other tissue), which gives a very short-lasting effect. The spleen is an organ found in all Vertebrate animals In humans the spleen is located in the abdomen of the body where it functions in the destruction of redundant Red In addition, there are many complications of such procedure.
A granuloma is a tumor containing granulocytes, and a "granulomatosis" is a necrotizing granuloma. In Medicine ( Anatomical pathology) a granuloma (classical Latin plural granulomata; modern anglicized plural granulomas, also accepted See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic Necrosis (in Greek Νεκρός = "dead" is the name given to unnatural Death of cells and living tissue.
There is usually a granulocyte chemotactic defect in individuals who suffer from insulin dependent diabetes mellitus. Chemotaxis, a kind of Taxis, is the phenomenon in which bodily cells bacteria, and other single-cell or Multicellular organisms direct their movements Diabetes mellitus type 1 (Type 1 diabetes Type I diabetes T1D T1DM IDDM juvenile diabetes is a form of Diabetes mellitus.
Additional images
 Blood cell lineage |
_diagram.png/120px-Hematopoiesis_(human)_diagram.png) Hematopoiesis |
See also
References
- ^ granulocyte at eMedicine Dictionary
- ^ polymorphonuclear+leukocyte at eMedicine Dictionary
External links
A complete blood count ( CBC) also known as full blood count ( FBC) or full blood exam ( FBE) or blood panel, is eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and booksDictionary
granulocyte
-noun
- (cytology, immunology) Any of various blood cells that have granules in their cytoplasm.
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