Immune and Lymphatic System I Flashcards
What is innate immunity?
immunity that lacks specificity and memory. Neutrophils are the first responders.
What is acquired immunity?
immunity that has specificity and memory. It takes longer to develop and includes humoral immunity.
What cells are highly involved in innate immunity?
neutrophils
What is passive immunity?
temporary immunity due to donated antibodies.
What is active immunity?
long lasting/permanent immunity due to self exposure to antigen resulting in memory T cells and B cells specific for antigen.
What is humoral immunity?
Antibody mediated immunity; it includes the use of plasma cells.
What is cell-mediated immunity?
T cells, B cells and antigen-presenting cells
What is lymphoid tissue?
Tissue that appears in the body as a gradient from diffuse lymphoid tissue to aggregated lymphoid tissue to lymphoid organs.
What are the two types of lymphoid organs?
primary and secondary
What are primary lymphoid organs?
Thymus and the bone marrow. Precursor cells in this region mature into immunocompetent cells. Each cell is programmed to recognize a specific antigen.
Where do lymphocytes originate?
in primary lymphoid organs. They then take up residence in secondary lymphoid organs.
What are features of lymph follicles?
they are not enclosed within a capsule, occur singly or in aggregates, are sites of B cell localization and proliferation, and are transient.
What do primary follicles contain?
virgin B cells and dendritic reticular cells that have not been exposed to antigens.
What are secondary follicles?
follices derived from primary follicles that have been exposed to nonself antigens. They are not present at birth.
What are the two major regions of a secondary follicle?
the cortex (corona) and the germinal center.
What does the corona contain?
densely packed B lymphocytes.
What does the germinal center contain?
B lymphocytes, memory B cells, plasma cells, dendritic reticular cells.
What is diffuse lymphoid tissue made up of?
scattered clusters of plasma cells, macrophages and lymphocytes located in the connective tissue stroma and various other sites.
Where is aggregated lymphoid tissue found?q
beneath and in contact with the epithelium.
What are the 3 accessory cells (antigen-presenting cells)?
macrophages, dendritic cells and follicular dendritic cells
Where do all immune system cells originate?
in the bone marrow.
What protein activates pro-B cells?
interleukin-7
What does a pre-B cell receptor express after it is activated by interleukin-7?
pre-B cell receptor.
What makes up the B lymphogute antigen receptor complex?
Igbeta, IgAlpha, ITAM
If a self-antigen binds strongly to a B cell, what occurs?
The B cell undergoes apoptosis.
If a self antigen does not bind strongly to a B cell, what occurs?
it survives and enters blood circulation.
The maturation of B cells involves the appearance of what cell surface receptors?
IgM and IgD, MCH class II proteins, complement receptors, Ig Fc receptors.
What are the 5 classes of antibodies?
IgA, D, G, M, E
What is the Fab fragment of an antibody?
The part of the antibody that recognizes the antigens. It is highly variable.
That is the Fc fragment of an antibody?
The part of the antibody that binds to a cell membrane.