Immune System Flashcards
What is the 1st line of defense?
Intact skin and mucous membranes
What is the 2nd line of defense?
Innate Immunity: neutrophils/macrophages + complement proteins)
What is the 3rd line of defense?
Acquired/Adaptive-Immunity (T-cells + antibodies proteins)
Differences between innate VS. acquired immunity.
- No memory VS. memory
- Non-specific VS. highly specific
- Effective prior to exposure VS. after exposure
- No change in effectiveness after exposure VS. increase in effectiveness
What are the 2 main components of acquired/adaptive immunity?
Humoral VS. Cell-mediated
What is Humoral immunity mediated by?
Antibodies (immunoglobulins) produced by plasma cells (derived from B-cells)
B-cells (assisted by Helper T-cells) –> plasma cells –> antibodies (Ab’s)
What is Cell-mediated immunity?
T-lymphocytes (helper + cytotoxic T-cells)
What is the function of the Helper T-cell?
Along with macrophages, protect against bacteria/fungi/protozoa + help B-cells differentiate into plasma cells (which produce Ab’s)
What is the Function of the Cytotoxic T-cell?
Defend against virus-infected cells
Describe the process of Adaptive immunity with a virus.
Virus engulfed by macrophage.
Antigen presenting cell (macrophage) with a Class II MHC protein signals Helper T cell with the same antigen receptor.
TH cell is activated and releases cytokines.
IL-2 (type of cytokine) is a T-cell growth factor and it expands the population of TH cells specific for this antigen.
Cytotoxic T-cells and B-cells (memory and plasma) are also activated.
What happens microscopically during inflammation?
Redness due to dilation of blood vessels. Inflammation from plasma entering tissue from the permeated blood vessels.
What are the 2 forms of inflammation?
Pyogenic: pus producing, primarily involves humoral immunity (antibodies) and neutrophils
Granulomatous: primarily involves cell-mediated immunity (T-cells) and macrophages
What are the functions of complement?
Increase vascular permeability causing edema and attracting neutrophils. Enhance phagocytosis and lysis of bacteria.
What are the advantages of the immune system?
Protect against infection + mediates recovery from infection.
What are the disadvantages of the immune system?
Hypersensitivity. Autoimmune disease. Symptoms of disease when infected cells are attracted.
In immunopathogenesis, what causes the disease?
Immune response, not an organism.
How does immunopathogenesis occur?
Antibody against the organism cross reacts with the host tissue. Cytotoxic T-cell kills the virus infected cells that would have died as a result of the virus itself.
What are the 2 types of immunization?
Active: Immunize with the actual microbe which may be killed or a live, attenuate (weakened) microbe
Passive: Immunize with antibodies previously made in another person/animal
What are the advantages of active immunization? Disadvantages?
Long Lasting; 7-10 days to become effective (not immediately protective)
What are the advantages of passive immunization? Disadvantages?
Protects immediately; lasts short time (1 month) + only protects against infections for which antibodies are effective (no cell-mediated immune response)
