Lymphatics Test Three Flashcards
Innate Immunity?
Lack immune specificity and memory Response is inflammation from neutrophils
Acquired Immunity?
Develops in response to antigens More powerful than innate Displays specificity and memory
Passive Immunity?
Temporary immunity due to donated antibodies-placental antibodies to fetus
Active Immunity?
Long lasting permanent immunity to self exposure to antigen resulting in T cells and B cells
Primary lymphoid organs?
Thymus and bone marrow
Secondary lymphoid organs?
Spleen lymph nodes tonsils
What is the difference between a primary and secondary lymphoid follicle(nodule)?
Primary are spherical and tightly packed virgin B cells and dentridritic reticular cells that have no antigen exposure.
Secondary are derived from primary follicles that have been exposed to antigetns and are not present at birth.
What are lymphoid follicles?
Not enclosed in capsule and can occur singly or in groups, site of B cell localization and proliferation, transient
What is a primary follicle (nodule)?
Spherical tightly packed virgin B cells and dendritic reticular cells not exposed to antigens.
What are secondary follicles (nodules)?
Nodules derived from primary follicles that have been exposed to nonself antigens-NOT present at birth.
Structure of a secondary lymph follicle?
Corona (cortex) composed of dense packed B lymphocytes and looks darker around the edges. Germinal center a central lighter stained region made of B lymphocytes memory B cells plasma cells dendritic reticular cells functioning as APC’s.
Vascular supply to a secondary lymph follicle?
Arteriole and venule supply the cortex a different arteriole and venule supply the center and lymph capillaries are NOT present.
What is diffuse lymphatic tissue?
Made of clusters of plasma cells, macrophages, and lymphocytes in the CT stroma. Lamina propria associated lymph tissues: MALT, BALT,GALT
What is aggregated lymphoid tissue?
Beneath and in contact with the epithelium including tonsils and peyers patches in the ileum
Where do all immune cells originate?
Bone marrow
Where do Immune cells go?
Immature T cells go to thymus and B cells go to specific regions in lymphoid tissues
What are the five classes of Antibodies?
IgA IgD IgG IgM IgE
Structure of an antibody?
Light and heavy chains, highly variable regions with a Fab fragment that recognizes the antigen, less variable region Fc fragment that binds antibody to cells
What is the function of MHC?
Presentation of antigenic peptides to T cells
MHC I?
Presented on surface of all cells except trophoblasts and RBC’s Requires CD8 and T cell antigen for binding
What is MHC II?
Expressed on surface of B cells and APC’s. CD4+ and T cells recognize peptide gragments of foreign proteins bound to MHC II on surface of APC’s
What are CD4+ T cells?
Recognize antigens bound to MHC class II molecules
What are Helper T cells?
Assist CD8+ cells differentiation and assist B cell differentiation.
What are CD8+ cells?
Cytolytic T cells bind to an APC releasing perforins and Fas ligand , recognize antigens bound to MHC I molecules, Undergo mitosis, Mediators of cellular immunity
CD16+ T cells?
Natural Killer Cells activated T cells by tumor cell antigens they release cytokines
What is T cell mediated immunity?
After the macrophage phagocytizes foreign material and presents antigens bound to MHC II complex to the helper T cell the T cell undergoes mitosis. Then the T cell attracts B cells and B cellls have access to free antigens and can undergo mitosis becoming memory B cells or plasma cells with the antibodies
What is the difference in parenchyma and stroma?
Parenchyma is cells that pack areas of lymphoid organ mostly lymphocytes. Stroma is reticular fibers and cells and undiffferentiated cells and fixed/free macrophages.
Identify
Trabecula of Lymph node
Identify
- Trabecula
- Sub-capsular sinus
- Germinal center of follicle
- Lymph follicle in cortex
Describe the medulla of a lymph node.
Irregular arrangement of loose medullary sinuses and dense medullary cords
- Sinuses lined with macrophages
- Cords with blood vessels lymphoblasts and plasma cells
Site of lymphocyte reentry to lymph stream
Identify
- Trabecula
- Germinal Center
- Lymph follicle in cortex
Secondary Node
Identify
Primary follicle
What is this?
Medulla of a lymph node
What is this?
Medulla of a lymph node
