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Chapter 37. The Lymphatic System and Immune Response. Lymphatic System. Lymphatic vessels Lymphatic tissues Tonsils Primary lymphatic organs Thymus and Bone marrow Secondary lymphatic organs Lymph nodes, spleen. Lymphatic System. Lymphatic System. Lymph Fluid lost from the capillaries
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Chapter 37 The Lymphatic System and Immune Response
Lymphatic System • Lymphatic vessels • Lymphatic tissues • Tonsils • Primary lymphatic organs • Thymus and Bone marrow • Secondary lymphatic organs • Lymph nodes, spleen
Lymphatic System • Lymph • Fluid lost from the capillaries • Edema • Functions of the lymphatic system: • Transport lymph to the blood vessels • Protects the body
Lymphatic vessels • Lymphatic capillaries • Lymphatic collecting vessels • Lymphatic trunk • Right lymphatic duct - drains lymph from: • Head right upper extremity • Right thorax • Drains into right subclavian vein
Lymphatic vessels • Thoracic duct – drains lymph from: • Rest of the body • Drains into left subclavian vein • Cisterna chyli • Characteristic of the lymphatic vessels • Walls with 3 tunics • Presence of valves • Presence of abundant anastomoses
Primary lymphoid organs • Bone marrow • Contain the stem cell that will give rise to all lymphocytes • Site of B cell differentiation or immunocompetency • Thymus • Site of T cell differentiation or immunocompetency
Secondary lymphatic organs • Lymph nodes • Bean-shaped • Numerous • Regional lymph nodes: • Cervical • Axillary • Inguinal, etc • Hilus • Afferent and efferent vessels
Secondary lymphatic organs • Microscopy • Capsule and subcapsular sinus • Trabecula • Cortex • Outer cortex (follicles) • Germinal center containing dividing B cells • Deep cortex or paracortical area • Contain T cells
Secondary lymphatic organs • Medulla • Medullary cords • Medullary sinuses • Contain macrophages and plasma cells
Secondary lymphatic organs • Spleen • Capsule • White pulp • Central artery • Lymphocytes • Red pulp • Venous sinuses • Reticular tissue • Macrophages arranged I splenic cords
Lymphoid tissues • Tonsils • One pharingeal • Two palatines • Two linguals • Presence of germinal center • Presence of crypts
The immune response • It is a systemic response • Destroys or neutralizes foreign substances • Characteristics of immune responses • Memory • Immunocompetent lymphocytes are monospecific • Specificity • Ability to differentiate self from nonself
The immune response • Antigens • Foreign proteins • Polysaccharides • Haptens • Lymphocytes • Responsible for the immune response • Autoimmunity
Organ, cells and cell interaction of the immune response • Stem cells that give rise to the immune system arise in the bone marrow • These cells will differentiate into B or T cells • B cells will stay in the bone marrow for maturation • T cells will migrate to thymus for maturation
Organ, cells and cell interaction of the immune response • B and T cells will then become immunocompetent • Specific cell-surface proteins that enable lymphocytes to bind to a particular antigen • B and T cell will then leave bone marrow and thymus, enter the blood stream and travel to secondary lymphatic organs • Site for clonal selection
Organ, cells and cell interaction of the immune response • B and T cell will bind to specific antigens and then undergo to clonal multiplication • B cell may become • Memory • Plasma cell • Humoral immunity
Organ, cells and cell interaction of the immune response • T cell may become • Memory • Cytotoxic • Helper • Supressor • Cellular immunity
Antibodies and tests for their presence • Characteristics of antibodies or Immunoglobulins (Igs) • Produced by plasma cells • They are plasma proteins (gamaglobulins) • Found in all body secretions
Antibodies and tests for their presence • Classes of antibodies • IgM, IgG, IgA, IgD, IgE • Structure of the immunoglobulins • 4 monomers • Linked together by disulfide bridges • 2 heavy chains • 2 light chains
Antibodies and tests for their presence • Heavy chains • Constant region (C) • Same amino acid sequence • Two of them • Variable region (V) • Different in all Igs • Formed in response to the antigens • Site for binding specific antigens
Antibodies and tests for their presence • Light chain • Constant region • Variable region • Immunoglobulins have a Y shape • Tests using antigen-antibody • Blood typing, pregnancy, Elisa (detects antigen or antibodies)