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(Above text modified from original article)
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Original file name: 1471-2105-10-387-3.jpg
{{Lymph node cartoons}}
 


==Reference==
===Reference===


<pubmed>19939270</pubmed>| [http://www.biomedcentral.com/1471-2105/10/387 BMC Bioinformatics.]
<pubmed>19939270</pubmed>| [http://www.biomedcentral.com/1471-2105/10/387 BMC Bioinformatics.]
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This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


 
Original file name: 1471-2105-10-387-3.jpg


[[Category:Immune]] [[Category:Cartoon]]
[[Category:Immune]] [[Category:Cartoon]]

Latest revision as of 12:38, 25 February 2012

Schematic representation of a lymph node internal architecture

Human lymph nodes are bean-shaped structures that range in size from a few millimeters to about 1-2 cm in their normal state. Internally, two main regions can be distinguished: the medulla and the cortex. The cortex can be further divided into an inner part, the paracortex (also called the T cell area), rich in T lymphocytes and an outer area, the node cortex that includes the B cell area consisting of follicles and germinal centers, where B cells are activated and differentiate. T and B areas are identified by high concentrations of different chemokines (CCR7 and CXCR5, respectively) secreted by local stromal cells. The whole structure is supported by a dense network of fibroblastic reticular cells that encloses small lymphatic channels of 10-15 μm in diameter along which small molecules are thought to diffuse.

  • T cell area - the paracortex
  • B cell area the node cortex
  • HEV - high endothelial venules are located inside the paracortex

A number of follicles are located in the node cortex, whereas the T cell area occupies the inner part.

The medulla consists of a part of the T-area that allows cells to exit by the efferent vessel. T and B cells enter the lymph node mainly from the blood, through HEV located inside the paracortex.

Absence of Infection

In the absence of an antigenic challenge, T and B cells randomly scan their respective areas for ~24-48 h before exiting the lymph node. Entrance of antigens into the lymph node triggers a series of events leading to antigen recognition and the activation of an immune response.

Infection

  • During an infection, lymphocyte recruitment from the periphery is enhanced due to a widening of the primary arteriole feeding the lymph node.
  • Once inside the lymph node, B and T cells rapidly home in their own compartments, following a specific chemotactic gradient.
  • T helper cells (TH) are the fastest (average velocity of 11 μm/min)
  • B cells (average velocity of 6 μm/min)
  • Dendritic cells (DCs) (average velocity of 3 μm/min)


(Above text modified from original article)


Lymph Node Cartoons: Detailed structure | Cartoon with Histology | Lymphocyte traffic | Simple structure | Simple node anatomy | Wiki node image | Internal structure | Mesenteric lymph node | Histology | Gallery | Lymph Node Development


Reference

<pubmed>19939270</pubmed>| BMC Bioinformatics.

Baldazzi et al. BMC Bioinformatics 2009 10:387 doi:10.1186/1471-2105-10-387


© 2009 Baldazzi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Original file name: 1471-2105-10-387-3.jpg

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Yi efo/eka'e gwa ebo wo le nyangagi wuncin ye kamina wunga tinya nan

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current13:05, 22 December 2010Thumbnail for version as of 13:05, 22 December 2010600 × 450 (66 KB)S8600021 (talk | contribs)==Schematic representation of a lymph node internal architecture== * T cell area - the paracortex * B cell area the node cortex A number of follicles are located in the node cortex, whereas the T cell area occupies the inner part. The medulla consist