Changes

<p>Plasma cells are oval, around 9µm and have a round prominent nucleus. The cytoplasm is extensive and stains strongly basophilic. It contains large amounts of rough endoplasmic reticulum and the Golgi apparatus is large and appears as a clear crescent-shaped structure near the nucleus. Some plasma cells accumulate considerable quantities of, perhaps abnormal, antibody and this appears as a large eosinophilic blob filling the cytoplasm and displacing the nucleus to one side. These blobs are called "Russell Bodies".</p>

<p>Plasma cells are oval, around 9µm and have a round prominent nucleus. The cytoplasm is extensive and stains strongly basophilic. It contains large amounts of rough endoplasmic reticulum and the Golgi apparatus is large and appears as a clear crescent-shaped structure near the nucleus. Some plasma cells accumulate considerable quantities of, perhaps abnormal, antibody and this appears as a large eosinophilic blob filling the cytoplasm and displacing the nucleus to one side. These blobs are called "Russell Bodies".</p>

===Function===

===Function===

<p>Plasma cells produce immunoglobulins/antibodies (thousands a second). The immunoglobulin binding specificity is identical to the binding specificity of the BCR on the [[Lymphocytes - WikiBlood#B cells|B cell]] that the cell has differentiated from. This means that when a [[Lymphocytes - WikiBlood#B cells|B cell]] has a BCR that can effectively bind to an antigen the immunoglobulins produced by the plasma cell can bind to that antigen.</p>

<p>Plasma cells produce immunoglobulins/antibodies (thousands a second). The immunoglobulin binding specificity is identical to the binding specificity of the BCR on the [[Lymphocytes - WikiBlood#B cells|B cell]] that the cell has differentiated from. This means that when a [[Lymphocytes - WikiBlood#B cells|B cell]] has a BCR that can effectively bind to an antigen the immunoglobulins produced by the plasma cell can bind to that antigen.</p>

<p>Although they can live for months most plasma cells only live for a few days and do not replicate in this time.</p>

<p>Although they can live for months most plasma cells only live for a few days and do not replicate in this time.</p>

Interaction of a B-cell with antigen results in clonal expansion, as does activation by T-cells. The majority of B-cell clones mature into plasma cells. Plasma cells are found in the splenic [[Spleen - Anatomy & Physiology#Red Pulp|red pulp]], [[Lymph Nodes - Anatomy & Physiology#Lymph Nodes|lymph node medulla]] and [[Bone Marrow - Anatomy & Physiology|bone marrow]]. Plasma cells are the terminal differentiation state of B-cells. They migrate to the medullary cords where their whole function is to secrete antibody.

Interaction of a B-cell with antigen results in clonal expansion, as does activation by T-cells. The majority of B-cell clones mature into plasma cells. Plasma cells are found in the splenic [[Spleen - Anatomy & Physiology#Red Pulp|red pulp]], [[Lymph Nodes - Anatomy & Physiology#Lymph Nodes|lymph node medulla]] and [[Bone Marrow - Anatomy & Physiology|bone marrow]]. Plasma cells are the terminal differentiation state of B-cells. They migrate to the medullary cords where their whole function is to secrete antibody.

===Class switching===

===Class switching===

<p>Initially plasma cell produce [[Immunoglobulin M - WikiBlood|IgM]] however this is not always the most appropriate Ig to be produced and therefore stimulation by [[Lymphocytes - WikiBlood#Helper CD4+|T cells]] and interleukins causes the plasma cells to undergo class switching to produce different classes of Ig.

<p>Initially plasma cell produce [[Immunoglobulin M - WikiBlood|IgM]] however this is not always the most appropriate Ig to be produced and therefore stimulation by [[Lymphocytes - WikiBlood#Helper CD4+|T cells]] and interleukins causes the plasma cells to undergo class switching to produce different classes of Ig.