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Mast cells

2013-10-23T14:23:37Z

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Mast Cells are granulated white blood cells cells ([[Leucocytes|leucocytes)]] that play an important part in the  [[Immune response|immune response]]. They release granules containing inflammatory mediators such as [[Histamine|Histamine]] and [[Heparin|Heparin]] which is an [[Anticoagulant|anticoagulant]] <ref>Alberts et al. Molecular biology of the cell 5th edition. (2008) Garland Science Taylor Francis New York. Chapter 13 Page 804</ref>  when tissue is injured or can be activated by [[Compliment proteins|compliment proteins]].

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Mast cells

2013-10-17T15:08:56Z

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Mast Cells are granulated white blood cells cells ([[leucocytes|leucocytes)]] that play an important part in the  [[Immune_response|immune response]]. They release granules containing inflammatory mediators such as [[Histamine|Histamine]] and [[heparin|Heparin]] which is an anticoagulant <ref>Alberts et Al. Molecular biology of the cell 5th edition. (2008) Garland Science Taylor Francis New York. Chapter 13 Page 804</ref>  when tissue is injured or can be activated by compliment proteins.<ref>Prussin C, Metcalfe DD (2003). "IgE, mast cells, basophils, and eosinophils". J Allergy Clin Immunol 111 (2 Suppl): S486–94. doi:10.1067/mai.2003.120. PMID 12592295.</ref>

 

 

 

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Mast cells

2013-10-17T15:05:47Z

120033920:

Mast Cells are granulated white blood cells cells play an important part in the initial immune response. They release granules containing inflammatory mediators such as Histamine and Heparin <ref>Alberts et Al. Molecular biology of the cell 5th edition. (2008) Garland Science Taylor Francis New York. Chapter 13 Page 804</ref>  when tissue is injured or can be activated by compliment proteins.<ref>Prussin C, Metcalfe DD (2003). "IgE, mast cells, basophils, and eosinophils". J Allergy Clin Immunol 111 (2 Suppl): S486–94. doi:10.1067/mai.2003.120. PMID 12592295.</ref>

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Mast cells

2013-10-17T15:03:26Z

120033920:

Mast Cells are granulated white blood cells cells play an important part in the initial immune response. They release granules containing inflammatory mediators such as Histamine and Heparin<references />  when tissue is injured or can be activated by compliment proteins.<ref>Prussin C, Metcalfe DD (2003). "IgE, mast cells, basophils, and eosinophils". J Allergy Clin Immunol 111 (2 Suppl): S486–94. doi:10.1067/mai.2003.120. PMID 12592295.</ref>

Mast cells

2013-10-17T15:01:46Z

120033920: Created page with "Mast Cells are granulated white blood cells cells play an important part in the initial immune response. They release granules containing inflammatory mediators such as Hist..."

Mast Cells are granulated white blood cells cells play an important part in the initial immune response. They release granules containing inflammatory mediators such as Histamine and Heparin<ref>Alberts,Johnson,Lewis,Raff (2008) Molecular Biology of the cell, 5th Edition, Garland science New York. Chapter 13 Page 804</ref>  when tissue is injured or can be activated by compliment proteins.<ref>Prussin C, Metcalfe DD (2003). "IgE, mast cells, basophils, and eosinophils". J Allergy Clin Immunol 111 (2 Suppl): S486–94. doi:10.1067/mai.2003.120. PMID 12592295.</ref>

Paramecium Cells

2012-11-27T00:31:24Z

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[[Eukaryotic cells|''Paramecium'' cells]] are unicellular organisms. They are part of the [[Eukaryotes|eukaryotic]] family. Thus they have membrane-bound [[Organelles|organelles]].

Paramecium is free living  ciliated [[Protozoa|Protozoa]], its cell body is surrounded by [[Cilia|cilia]]; . The function of the cilia is to allow paramecium to move around in its freshwater habitat, they are also used to waft small bacteria and algaes into the gullet (a large invagination in the cell membrane) where they are endocytosed and assymilated into the cell. All waste excess is exctreted via the anal pore. Paramecium lives in a freshwater environment which in the abscence of [[Contractile vacuole|contractile vacuoles]] would burst this is caused by the [[Osmosis|osmotic]] uptake of water, by a process known as [[Osmoregulation|osmoregulation]] <ref name="(Beale G. & Preer J,2008).">Beale, Goffey and Preer, John R. Jr. (2008) Paramecium Genetics and Epigenetics CRC Press, Taylor and Francis Group.</ref>. The Paramecium cell reproduces by a process called [[Reproduction by Conjugation|conjugation]].<ref>L.Prescott, J.Hardley and D.Klein Microbiology 6th Edition New York:McGraw-Hill</ref> and[[asexual fission|asexual fission]] asexual fission creates two genetically identical daughter cells. Paramecium has action potentials not unlike those that occur in [[Neuron|neurons ]] calcium ions enter the cell through voltage gated channels and cause the rapid depolarisation of the cell and generate an action potential. The repolarising phase is due to the closing of the calcium ion channels and the opening of the potassium ion channels The length of a typical [[Cell|''paramecium'']] varies from 100 μm to 300 μm <ref>Brock Biology of Micro-organisms 12th Edition, Madigan Dunlap Clark, Pg 69</ref>. They can be found in freshwater areas, like ponds and lakes. 

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Neurone cell

2012-11-26T23:28:48Z

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= Neurones are excitable cells that make up the [[Nervous system|nervous system]]. On average a neurone is 20-30µm in diameter, however this varies depending on the type of neurone. A neurone has four main sections; the dendrites, cell body, axon and axon terminals. The axon is where [[Saltatory conduction|saltatory conduction]] causes the [[Propagation|propagation]] of an [[Action potential|action potential]] to move down the axon towards the axon terminal. The axon terminal is where [[Presynaptic modulation|presynaptic modulation]] occurs, and where neurotransmitters are released causing the action potential to be passed to another neurone across the synapse. The dendrites are where [[Graded potentials|graded potentials]] occur. These can either be excitatory postsynaptic potential (EPSP) or inhibitory postsynaptic potential (IPSP). A graded potential is a subthreshold voltage (below -55mV) however if a number of graded potentials sum together at the axon hillock this can lead to a suprathreshold value and and an action potential is generated.  =

Neurones have a resting membrane potential (RMP), this is set up by a potassium ion leak channel. This allows potassium to move by [[Facilitated diffusion|facilitated diffusion]] from inside the cell out, down its concentration gradient, creating a slightly positive charge on the outside of the membrane compared to the inside. RMP is also set up by an [[ATP-ase|ATP-ase]] pump, sodium and potassium. This uses ATP to pump, against their concentration gradients, three sodium outside the cell and two potassium back in. This is a [[Symporter|symport]] protein channel. Both of these ion movements causes the inside of the cell to be slightly negative when compared to the outside, usually around -70mV. This is the resting membrane potential for a neurone. 

 '''References''' === Mathews G. (2003) Cellular Physiology of Nerve and Muscle, 4th Edition, Oxford: Blackwell Pub.