FACTOID # 30: If Alaska were its own country, it would be the 26th largest in total area, slightly larger than Iran.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Phagocytosis" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Phagocytosis
Steps of a macrophage ingesting a pathogen:a. Ingestion through phagocytosis, a phagosome is formedb. The fusion of lysosomes with the phagosome creates a phagolysosome; the pathogen is broken down by enzymesc. Waste material is expelled or assimilated (the latter not pictured)Parts:1. Pathogens2. Phagosome3. Lysosomes4. Waste material5. Cytoplasm6. Cell membrane
Steps of a macrophage ingesting a pathogen:
a. Ingestion through phagocytosis, a phagosome is formed
b. The fusion of lysosomes with the phagosome creates a phagolysosome; the pathogen is broken down by enzymes
c. Waste material is expelled or assimilated (the latter not pictured)

Parts:
1. Pathogens
2. Phagosome
3. Lysosomes
4. Waste material
5. Cytoplasm
6. Cell membrane

Phagocytosis is the cellular process of engulfing solid particles by the cell membrane to form an internal phagosome, or "food vacuole". The phagosome is usually delivered to the lysosome, an organelle involved in the breakdown of cellular components, which fuses with the phagosome. The contents are subsequently degraded and either released extracellularly via exocytosis, or released intracellularly to undergo further processing. Image File history File links This is a lossless scalable vector image. ... Image File history File links Download high resolution version (2352x1611, 185 KB) Summary A happy macrophage ingesting not so happy pathogens Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version... Image File history File links Download high resolution version (2352x1611, 185 KB) Summary A happy macrophage ingesting not so happy pathogens Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version... A phagolysosome is a membrane-bound organelle which is formed from the fusing of a lysosome and a phagosome. ... This article or section is in need of attention from an expert on the subject. ... A pathogen or infectious agent is a biological agent that causes disease or illness to its host. ... In cell biology, a vacuole formed around a particle absorbed by phagocytosis. ... Organelles. ... It has been suggested that Cytoplast be merged into this article or section. ... The cell membrane (also called the plasma membrane, plasmalemma or phospholipid bilayer) is a semipermeable lipid bilayer common to all living cells. ... 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... The cell membrane (also called the plasma membrane, plasmalemma or phospholipid bilayer) is a semipermeable lipid bilayer common to all living cells. ... In cell biology, a vacuole formed around a particle absorbed by phagocytosis. ... Organelles. ... Schematic of typical animal cell, showing subcellular components. ... This page is currently under construction. ...


Phagocytosis is involved in the acquisition of nutrients for some cells, and in the immune system is a major mechanism used to remove pathogens and cell debris. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytosed. A scanning electron microscope image of a single neutrophil (yellow), engulfing anthrax bacteria (orange). ... A pathogen or infectious agent is a biological agent that causes disease or illness to its host. ...


Phagocytosis is a specific form of endocytosis involving the vesicular internalization of solid particles, such as bacteria, and is therefore distinct from other forms of endocytosis such as pinocytosis, the vesicular internalization of liquids. It has been suggested that Endocytic cycle be merged into this article or section. ... This article or section is in need of attention from an expert on the subject. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Pinocytosis or cell drinking is one of three forms of endocytosis, a cellular process that is used to take up smaller particles in cell by splitting in small particles , and forms vesicles which then merge with lysosomes to hydrolyze (hydrolytic enyzmes) to break down the particles. ...

Contents

Etymology

Phagocytosis is named from Greek roots: phagein - to eat, kytos - cell, and -osis - a suffix indicating a process. As such, it can be translated literally as "the cellular process of eating". It should be noted that the process is not entirely homologous to eating, as the purpose is to eliminate debris and pathogen, as opposed to taking in fuel for cellular processes.


Phagocytic cells

Phagocyte Diagram
Neutrophil
Eosinophil
Basophil
Monocyte
Macrophage
Dendritic cell

Many protists are able to phagocytose particles, however in animals, phagocytosis is performed by specialized cells called phagocytes, which are able to remove foreign bodies and thus fight infection. In humans and many other animals, phagocytes include macrophages, monocytes, dendritic cells, and granulocytes[1]. The term professional phagocytes can be used to describe both macrophages and neutrophils, as these cells are considered to have phagocytosis as their primary function[2]. 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 Neutrophil. ... Eosinophils are white blood cells that are responsible for combating infection by parasites in the body. ... Image File history File links Eosinophil2. ... This article or section does not cite its references or sources. ... Image File history File links Basophil. ... Monocyte A monocyte is a leukocyte, part of the human bodys immune system that protect against blood-borne pathogens and move quickly to sites of infection in the tissues. ... Image File history File links Monocyte. ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, makros = long, phagein = eat) are white blood cells, more specifically phagocytes, acting in the nonspecific defense as well as the specific defense system of vertebrate animals. ... Image File history File links Macrophage. ... Dendritic cells (DC) are immune cells and form part of the mammal immune system. ... Image File history File links Dendritic_cell. ... Typical phyla Chromalveolata Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Cabozoa Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: (RP); (GenAm)), Greek protiston -a meaning the (most) first of all... A phagocyte is a cell that ingests and destroys foreign matter such as microorganisms or debris via a process known as phagocytosis. ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, makros = long, phagein = eat) are white blood cells, more specifically phagocytes, acting in the nonspecific defense as well as the specific defense system of vertebrate animals. ... Monocyte A monocyte is a leukocyte, part of the human bodys immune system that protect against blood-borne pathogens and move quickly to sites of infection in the tissues. ... Dendritic cells (DC) are immune cells and form part of the mammal immune system. ... Eosinophil granulocyte Basophil granulocyte Granulocytes are a category of white blood cells characterised by the presence of granules in their cytoplasm. ...


A great body of evidence continues to mount showing that resident, neighbouring cells in a tissue will phagocytize their apoptotic neighbours, thus maintaining tissue homeostasis. This clearance can, depending on the location, facilitate greater clearance than that achieved by resident macrophages.[citation needed] A section of mouse liver showing an apoptotic cell indicated by an arrow // Apoptosis is a process of deliberate life relinquishment by a cell in a multicellular organism. ...


== ==Functions== ==


Innate immunity

In humans, the most important facet of phagocytosis is its control of inflammation. Depending on the phagocytosed particle, phagocytosis can induce inflammation or, as is the case with apoptotic cells, induce resolution of inflammation. Phagocytosis is also involved in immune tolerance, which prevents inflammation against normal components of the body[citation needed].


Adaptive immunity

For the activation of the adaptive immune response, phagocytosis is a necessary activation step. A T helper cell must be presented foreign particles bound to the major histocomptability complex class II (MHC II) receptor to become activated. The immune system is the collection of organs and tissues involved in the adaptive defense of a body against foreign biological material. ... This article or section does not cite its references or sources. ... The major histocompatibility complex (MHC) is a large genomic region or gene family found in most vertebrates. ...


Nutrition

In many protists, phagocytosis is used as a means of feeding, providing part or all of their nourishment. This is called phagotrophic nutrition, as distinguished from osmotrophic nutrition, which takes place by absorption. In some, such as amoebae, phagocytosis takes place by surrounding the target object with pseudopods, as in animal phagocytes. In other protozoa, for instance, ciliates, there is a specialized groove or chamber in the cell where phagocytosis takes place, called the cytostome or mouth. The resulting phagosome may be merged with lysosomes containing digestive enzymes, forming a phagolysosome. The food particles will then be digested, and the released nutrients diffused or transported into the cytosol to use in other metabolic processes. Typical phyla Chromalveolata Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Cabozoa Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: (RP); (GenAm)), Greek protiston -a meaning the (most) first of all... Alternate meanings: Amoeboid, Amoebozoa For other uses, see Amoeba (disambiguation). ... Pseudopods or pseudopodia (false feet) are temporary projections of eukaryotic cells. ... Classes Karyorelictea Heterotrichea Spirotrichea Litostomatea Phyllopharyngea Nassophorea Colpodea Prostomatea Oligohymenophorea Plagiopylea See text for subclasses. ... A cytostome or cell mouth is a part of a cell specialized for phagocytosis, usually in the form of a microtubule-supported funnel or groove. ... In cell biology, a vacuole formed around a particle absorbed by phagocytosis. ... Organelles. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... The cytosol (cf. ...


Resistance to phagocytosis

A macrophage with two cell membrane extentions reaching to engulf particles
A macrophage with two cell membrane extentions reaching to engulf particles

A substance or process which impedes or prevents the action of phagocyctes is termed antiphagocytic. Additionally, some bacteria may need to be opsonized before they are recognised as particles to be phagocytosed[citation needed]. 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 linksMetadata Download high resolution version (1280x1024, 279 KB) Summary A macrophage of a mouse stretching itself to eat two smaller particles, possibly pathogens. ... This page is a candidate to be moved to Wiktionary. ...


Certain intracellular pathogens, such the bacterial agents of leprosy and tuberculosis, are resistant to lysosomal degradation once internalised via phagocytosis. For the malady found in the Hebrew Bible, see the article Tzaraath. ... Tuberculosis (abbreviated as TB for tubercle bacillus) is a common and deadly infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis. ... Organelles. ...


Media

  • Phagocytosis by neutrophils ( file info) — Watch in browser
    • A rapidly moving neutrophil can be seen taking up several conidia over an imaging time of 2 h with one frame every 30 s.
  • Phagocytosis by dendritic cells ( file info) — Watch in browser
    • A single dendritic cell can be seen here efficiently taking up at least four conidia in its vicinity.
  • Phagocytosis by macrophages ( file info) — Watch in browser
    • An active J774 macrophage is seen taking up at least three conidia. The J774 cells were treated with 5 ng/ml interferon-γ one night before filming with conidia. The observation was made over a period of 2.5 h every 30 s.
  • 3-D Reconstruction of phagocytosis ( file info) — Watch in browser
    • A 3-D reconstruction of a z stack showing a fixed neutrophil that has ingested five conidia and has one conidia on the surface. The actin cytoskeleton of the neutrophil is seen here in green, while the conidia are seen in red.
  • Problems seeing the videos? See media help.

Image File history File links S1-Polymorphonuclear_Cells_with_Conidia_in_Liquid_Media. ... Conidia are asexual spores of fungus. ... Image File history File links S6-Dendritic_Cells_with_Conidia_in_Collagen. ... Image File history File links S4-J774_Cells_with_Conidia_in_Liquid_Media. ... Interferon-gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. ... Image File history File links S9-Conidia_Can_Be_Attached_to_the_PMN_Surface_or_Truly_Internalized. ... The focal plane of a lens is a plane that is perpendicular to the axis of the lens and passes through its focus. ... A fixative is a liquid, similar to varnish, which is usually sprayed over a finished piece of artwork to better preserve it and prevent smudging. ... G-Actin (PDB code: 1j6z). ... The eukaryotic cytoskeleton. ...

See also

An antigen presenting cell (APC) is a cell that displays foreign antigen complexed with MHC on its surface. ... Antigen presentation is a process in the bodys immune system by which macrophages, dendritic cells and leukocytes capture antigens and then carry those antigens to T-cells. ...

References

  1. ^ Prescott, L. (1993). Microbiology, Wm. C. Brown Publishers, ISBN 0-697-01372-3
  2. ^ Immunology at MCG 1/phagocyt

In 1828 the Medical Academy of Georgia was chartered by the state of Georgia with plans to offer a single course of lectures leading to a bachelors degree. ...

External links


  Results from FactBites:
 
Phagocytosis (360 words)
Phagocytosis is mediated by macrophages and polymorphonuclear leucocytes.
Phagocytosis involves the ingestion and digestion of the following:
This coating of the organisms by molecules that speed up phagocytosis, is termed 'opsonization', and the Fc portion of antibody, and C3 are termed 'opsonins'.
Immunodeficiency disorders (984 words)
When the immune system detects an antigen, it responds by producing antibodies that destroy the harmful substances.
The immune system response also involves a process called phagocytosis.
During this process, certain white blood cells swallow and destroy bacteria and other foreign substances.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m