The Lymphatic System and Immune Response Exercise 38 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 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

Lymphatic vessels

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

Thymus

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

Spleen

Lymphoid tissues Tonsils One pharingeal Two palatines Two linguals Presence of germinal center Presence of crypts

Tonsils

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 Hemocytoblasts in the bone marrow give rise to lymphocytes Types of Lymphocytes: B - will stay in the bone marrow for maturation (immunocompetence) T - will migrate to thymus for maturation (immunocompetence) Natural Killers

Organ, cells and cell interaction of the immune response 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 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 Suppressor Cellular immunity

Antibodies and tests for their presence Characteristics of antibodies or Immunoglobulins (Igs) Produced only 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 2 heavy chains 2 light chains

Antibody