Tissues of the Immune Response

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Tissues of the Immune Response

• Hugh B. Fackrell
• Filenametissuesv7

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Structure and Function of the Lymphatic System

• Lymphatic system
• Primary Lymphoid tissues
• Secondary Lymphoid Tissues
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Lymphatic System Function

• Generate lymphocytes committed to a particular
  antigenic specificity
• Create an environment to trap antigens from
  various tissues, spaces or fluids
• Provide sites where the committed lymphocytes
  interact with the trapped antigens
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Committed Lymphocytes

• Immature lymphocytes
• generated by hematopoiesis of pleuripotent stem
  cells within the bone marrow.
• Lymphocytes mature in the primary lymphoid organs
• Bone Marrow, Thymus, Bursa (in birds)
• Mature lymphocytes migrate to the secondary
  lymphoid organs
• Lymph nodes, spleen, mucosal associated lymphoid
  tissues

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Primary Lymphoid Tissues

• B cells
• Birds
• Bursa of Fabricius
• Mammals
• Fetal Liver
• Bone Marrow
• T Cells
• Thymus

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Bursa

• Location
• Structure
• Function

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Avian Lymphoid System
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Bursa of FabriciusFollicles
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Bursa of Fabricius X-Section
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Bursa B cell germinal centers
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B cell Origins

• Hemopoietic stem cells develop in the fetal liver
• Later they are produced in the Bone Marrow
• Bursal equivalent
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Fetal liver Hematopoiesis
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Bone Marrow Scanning EM
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Bone Marrow Differentiation
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Thymus

• Location
• Structure
• Circulation
• Function
• Summary Diagram

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Thymus Location
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Thymus Lobules
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Thymus X section
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Thymus Development
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Thymus Embrogenisis
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Thymus Summary Diagram
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Athymic Mouse

• Nude mouse - lacks hair follicles
• Lacks developed thymus
• few circulating T cells
• No cell mediated immunity

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Nude Mouse
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Lymph Nodes

• Distribution
• Structure
• Circulation
• Function
• Summary Diagram

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Lymphatic System
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Node Circulation
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Node TD TI areas
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Node X section
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Node Diagram 2
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Cortex
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Node Diagram
Primary Follicle
Efferent lymphatic
Afferent lymphatic
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Node B cells in cortex
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Node Germinal Center
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Node Reticular network
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Node Follicle Mantle of lymphocytes
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Paracortex
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Node T Cells Diffuse cortex
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Node T Cells in Paracortex
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Node T cell depletion
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Medulla

• Thymic Dependent area
• T cells localize

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Lymph Node Medulla
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Node LM Medulla
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Node Medullary Sinus
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Node Subcapsular Sinus
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Node EM of Medulla
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Node Primary Follicle
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Node Diffuse Cortex
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Node HEV
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Node Diagram summary
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Spleen

• Location
• Structure
• Circulation
• Immunological function
• Summary Diagram

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Spleen Connective Tissue
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Spleen X section low mag
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Spleen X section higher mag
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Spleen circulation
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Spleen EM Marginal zone
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Marginal zone B cells
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Antigen localization in Spleen
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Spleen Summary Diagram
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The End