Changes

<p> The parenchyma is supported by a fine mesh of reticular fibres and is divided into two types of tissue, the red and the white pulp. The red and white pulp are separated by the marginal sinus.</p>

<p> The parenchyma is supported by a fine mesh of reticular fibres and is divided into two types of tissue, the red and the white pulp. The red and white pulp are separated by the marginal sinus.</p>

===Red Pulp===

===Red Pulp===

<p>The red pulp makes up the majority of the spleen and is composed of a network of cell cords in series with vascular sinuses. The splenic cords contain [[Macrophages - Anatomy & Physiology|macrophages]], [[B cell differentiation- Anatomy & Physiology#Plasma cells|plasma cells]], [[Lymphocytes - Anatomy & Physiology|lymphocytes]] and other mature blood cells e.g. [[Granulocyte - Anatomy & Physiology|granulocytes]] and [[Erythrocyte - Anatomy & Physiology|erythrocytes]].  While the vascular sinuses are wide vascular channels lined with endothelial cells. Blood cells and fluid can pass into the splenic cords through fenestrations in the sinus walls. </p>

<p>The red pulp makes up the majority of the spleen and is composed of a network of cell cords in series with vascular sinuses. The splenic cords contain [[Macrophages - Anatomy & Physiology|macrophages]], [[B cell differentiation- Anatomy & Physiology#Plasma cells|plasma cells]], [[Lymphocytes - Anatomy & Physiology|lymphocytes]] and other mature blood cells e.g. [[Granulocyte - WikiBlood|granulocytes]] and [[Erythrocyte - Anatomy & Physiology|erythrocytes]].  While the vascular sinuses are wide vascular channels lined with endothelial cells. Blood cells and fluid can pass into the splenic cords through fenestrations in the sinus walls. </p>

===White Pulp===

===White Pulp===

<p>White pulp is organised in relation to the splenic arterioles and consists of discrete lymphoid tissue surrounding a central arteriole. There is a sheath of [[Lymphocytes - Anatomy & Physiology#T cells|T cells]] directly around the arteriole, the periarteriolar lymphoid sheath (PALS), which is surrounded by a marginal sinus, and then a zone of [[Lymphocytes - Anatomy & Physiology#B cells|B cells]] and [[Macrophages - Anatomy & Physiology|macrophages]] (the marginal zone). B cell follicles are associated with the marginal zone and expand and develop germinal centres after antigen activation. The marginal sinuses are linked to the red pulp sinuses. </p><p>White pulp stains basophilc in a H&E stain</p>

<p>White pulp is organised in relation to the splenic arterioles and consists of discrete lymphoid tissue surrounding a central arteriole. There is a sheath of [[Lymphocytes - Anatomy & Physiology#T cells|T cells]] directly around the arteriole, the periarteriolar lymphoid sheath (PALS), which is surrounded by a marginal sinus, and then a zone of [[Lymphocytes - Anatomy & Physiology#B cells|B cells]] and [[Macrophages - Anatomy & Physiology|macrophages]] (the marginal zone). B cell follicles are associated with the marginal zone and expand and develop germinal centres after antigen activation. The marginal sinuses are linked to the red pulp sinuses. </p><p>White pulp stains basophilc in a H&E stain</p>