Changes

''For haemolymph nodes click [[Haemolymph Nodes - Anatomy & Physiology|here]]''

''For haemolymph nodes click [[Haemolymph Nodes - Anatomy & Physiology|here]]''

[[Image:LH_Lymph_Node_Gross_Histology.jpg|thumb|150px|right|<p>'''Gross view'''</p>^{©Nottingham Uni 2008}]]

[[Image:LH_Lymph_Node_Gross_Histology.jpg|thumb|150px|right|<p>'''Gross view'''</p>^{©Nottingham Uni 2008}]]

<p>The body contains hundreds of lymph nodes of varying size (1-20mm) and these are located along the routes of lymphatic vessels. They are found throughout the body but are more concentrated in the axilla, groin and mesenteries. Lymph nodes act as a filter for the lymph removing antigens and releasing immune-competent cells and immunoglobulins.</p>

<p>Part of the [[Lymphatic System - Anatomy & Physiology|lymphatic system]], the body contains hundreds of lymph nodes of varying size (1-20mm) and these are located along the routes of lymphatic vessels. They are found throughout the body but are more concentrated in the axilla, groin and mesenteries. Lymph nodes act as a filter for the lymph removing antigens and releasing immune-competent cells and immunoglobulins.</p>

==Development==

==Development==

<p>Lymph nodes develop from lateral plate mesoderm in paired sacs from lymphatic vessels. These sacs undergo remodelling and endothelial and mesenchymal outgrowths form the meshwork of channels and spaces that produces the cortex-medulla structure. Lymphocytes then populate the cortex and medulla. The sub-capular sinus is a remainder of the lymphatic vessel.</p>

<p>Lymph nodes develop from lateral plate mesoderm in paired sacs from lymphatic vessels. These sacs undergo remodelling and endothelial and mesenchymal outgrowths form the meshwork of channels and spaces that produces the cortex-medulla structure. Lymphocytes then populate the cortex and medulla. The sub-capular sinus is a remainder of the lymphatic vessel.</p>

** Connect with para-trabecular sinuses and exit from efferent lymphatics on the node surface.

** Connect with para-trabecular sinuses and exit from efferent lymphatics on the node surface.

* Blood vessels enter and leave at the hilus</p>

* Blood vessels enter and leave at the hilus</p>

===Histology===

===Histology===

<gallery perrow="4" >

<gallery perrow="4" >

Image:LH_Lymph_Node_Follicular_layers_Histology.jpg|<p>'''Follicular layers'''</p>^{©RVC 2008}

Image:LH_Lymph_Node_Follicular_layers_Histology.jpg|<p>'''Follicular layers'''</p>^{©RVC 2008}

Image:LH_Lymph_Node_HEV_Histology.jpg|<p>'''High endothelial venule'''</p>^{©Nottingham Uni 2008}</gallery>

Image:LH_Lymph_Node_HEV_Histology.jpg|<p>'''High endothelial venule'''</p>^{©Nottingham Uni 2008}</gallery>

==Functions==

==Functions==

<p>As the spleen removes antigens from the blood, lymph nodes remove antigens from tissue. Antigen presenting cells (B and T cells) migrate from peripheral tissue via afferent lymphatic vessels to the lymph nodes where they present their antigen to lymphocytes. B cells and T cells enter via the high endothelial venules by diapedesis and B cells migrate to the cortex while T cells to the deep cortex.</p>

<p>The lymph nodes are [[Secondary Lymphoid Tissue - Anatomy & Physiology|secondary lymphoid tissue]], and as the spleen removes antigens from the blood, lymph nodes remove antigens from tissue/lymph. Antigen presenting cells (B and T cells) migrate from peripheral tissue via afferent lymphatic vessels to the lymph nodes where they present their antigen to lymphocytes. B cells and T cells enter via the high endothelial venules by diapedesis and B cells migrate to the cortex while T cells to the deep cortex.</p>

<p>Antibodies and immunologically competent cells leave the lymph nodes via the efferent lymphatics.</p>

<p>Antibodies and immunologically competent cells leave the lymph nodes via the efferent lymphatics.</p>

==In pathology==

==In pathology==

Lymph node pathology can be found [[Lymphoreticular/Haemotopoietic System - Lymph Nodes|here]]

Lymph node pathology can be found [[Lymphoreticular/Haemotopoietic System - Lymph Nodes|here]]