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→Phagocytosis
Neutrophils are the first inflammatory cells to enter damaged tissue from the blood after tissue damage has being caused. They are the predominant cell 4 - 6 hours after the beginning of an inflammatory reaction; at 12 hours there are also substantial numbers of [[Macrophages|macrophages]] and at 24 hours there are equal numbers of neutrophils and macrophages.
Neutrophils are the first inflammatory cells to enter damaged tissue from the blood after tissue damage has being caused. They are the predominant cell 4 - 6 hours after the beginning of an inflammatory reaction; at 12 hours there are also substantial numbers of [[Macrophages|macrophages]] and at 24 hours there are equal numbers of neutrophils and macrophages.
===Phagocytosis===
===Phagocytosis===
<p>The main role of the neutrophil is to engulf and destroy foreign material. They uptake this material via endocytosis and this surrounds the material in the neutrophil membrane forming a phagosome. Lysosomes inside the neutrophil then fuse with the phagosome and release their contents degrading the foreign material. Phagocytosing material shortens the lifespan of the neutrophil due to the build up of toxins both from the degraded bacteria etc. and also from its own lysosomes contents. Most neutrophils die after phagocytosing 5-25 bacteria and the dead neutrophils form [[Necrosis - Pathology#Pus Formation|pus]].</p>
<p>The main role of the neutrophil is to engulf and destroy foreign material. They uptake this material via endocytosis and this surrounds the material in the neutrophil membrane forming a '''phagosome'''. Lysosomes inside the neutrophil then fuse with the phagosome and release their contents degrading the foreign material. Phagocytosing material shortens the lifespan of the neutrophil due to the build up of toxins both from the degraded bacteria etc. and also from its own lysosomes contents. Most neutrophils die after phagocytosing 5-25 bacteria and the dead neutrophils form [[Necrosis - Pathology#Pus Formation|pus]].</p>
<p>Neutrophils do not always destroy engulfed particles and may transport engulfed particles to local lymph nodes to be dealt with by other host defence mechanisms. This means that acute inflammation in tissue is can be accompanied by similar acute inflammation in the lymph nodes.</p>
<p>Neutrophils do not always destroy engulfed particles and may transport engulfed particles to local lymph nodes to be dealt with by other host defence mechanisms. This means that acute inflammation in tissue is can be accompanied by similar acute inflammation in the lymph nodes.</p>
====Recognition====
====Recognition====
<p>Oxygen dependant killing requires the productions of reactive oxygen species that damage bacterial membranes. These species are generated during a burst of respiration following phagocytosis were increased amount of oxygen are used. Hydrochloric acid is also produced during this process.</p>
<p>Oxygen dependant killing requires the productions of reactive oxygen species that damage bacterial membranes. These species are generated during a burst of respiration following phagocytosis were increased amount of oxygen are used. Hydrochloric acid is also produced during this process.</p>
<p>Oxygen independent killing uses lysosomes, cathepsin (a protease) and other mechanisms. Lysozymes are particularly effective against gram positive bacteria as they hydrolyse the glycopeptides coats of the bacteria.</p>
<p>Oxygen independent killing uses lysosomes, cathepsin (a protease) and other mechanisms. Lysozymes are particularly effective against gram positive bacteria as they hydrolyse the glycopeptides coats of the bacteria.</p>
===Interactions===
===Interactions===
<p>Il-6, Il-8 and C5a are all chemoattractants for neutrophils.</p>
<p>Il-6, Il-8 and C5a are all chemoattractants for neutrophils.</p>