VBS.THE EXAM #2 QUESTIONS AND ANSWERS 100%

VBS.THE EXAM #2 QUESTIONS AND ANSWERS 100% naturally acquired active immunity develops after exposure to antigens in environment Artificially acquired immunity response to antigens introduced via a vaccine Neutralization virus is unable to attach because of the way the antibody is bound to the virus Antibody structure 1) Antigen-binding site 2) Variable regions of light and heavy chains 3) Constant regions of light and heavy chains 4) 2 light chains 5) 2 heavy chains Fab region of antibody variable region that binds antigen to form antigen-antibody complex What type of cell helps the B cell? T helper cells (TH cells) What type of cell is attacking this cancer cell? C-cytotoxic cells How do immune cells "recognize" cancerous cells? Must recognize the invader/cancer cell Cell-mediated Immunity Dendritic cells = sample the environment to see what they can find and present that info to the T cells How do T cells "see" antigens"? T cell sees antigens presented by dendritic cells (MHC proteins) Cell mediated Immunity The T cells are the effectors cells (doing the work) What type of cell detects antigens and then activates T cells? Dendritic cells How do T cells become activated? Can present with MHC I or MHC II Exterior II (T helper/CD4) Interior I (CD8) Dendritic (can do both, can activate T helper ( or CD4 cells) and C-cytotoxins (or CD8 cells) as well Dendritic cells are located in tissues 1. Cell extension can reach across mucous membranes to sample surface - PRRs on dendritic cells are the things hooking on to the antigens - Antigens are then brought into the cell and displayed via MHC 2. Dendritic cells monitor GI tract TH cells recognize antigens bound to MHCI 1. Dendritic cell 2. T cell receptor will have specific fit for antigen 3. CD4 molecule will recognize the MHC - Then the two cells become tightly connected - Macrophages release cytokines - Cytokines are received and activation occurs What is a CD marker? Stands for Cluster of Differentiation What do activated TH cells do? 1. Active B cells 2. Activate macrophages 3. Help Tc cells What do activated T cells do? 1. Kill cells that have bacteria/viral cells inside of them - B cells are extracellular 2. Kill cancer cells (apoptosis) Indice virally infected cells (apoptosis) 3. Indice virally infected cells (apoptosis) How do dendritic cells "recognize" antigens? PRRs (which they then display with MHC) TLRs (toll-like receptors) Receptors on the membrane of a phagocyte that allow it to find and bind to the PAMP receptors of various microbes. The Type of TLR that is bound determines the phagocyte response Where does T cell and B cell activation take place? Lymph nodes: 1. The lymph system absorbs the extra liquid and brings it back to the blood 2. It moves dendritic cells from where they saw the antigens to the 2 lymphoid organs where there are high densities of B and T cells - A lot of immune activity going on here (reason for swelling) What type of cell present antigens to the t cells in the 2 lymphoid organs? Dendritic cell 1 lymphoid organ thymus 1. The T cells are not ready so they leave the bone marrow and go to the thymus to finish out the maturation process 2. Tolerance: prevent immune disorder ( apoptosis keep them from recognizing you) 3. T cells with receptors that recognize self-epitopes are destroyed