IS Overview of the Immune System Flashcards
mechanism of immunity that is mediated by cells such as T-lymphocytes (T-cells) and natural killer cells
Cellular Immunity
cells attack and destroy infected or abnormal cells and is effective against intracellular pathogens (viruses)
Cellular Immunity
mechanism of immunity that is mediated by soluble molecules such as antibodies which are produced by B-lymphocytes (B-cells)
Humoral Immunity
neutralize or mark pathogens for destruction and is more effective against extracellular pathogens (bacteria)
Humoral Immunity
born with either inherited from parents or acquire in utero
Natural/Innate Immunity
- acquired through exposure to pathogens
- maternal antibodies transferred fetus via the placenta
- long lasting immunity
Natural/Innate Immunity
2 types of acquired immunity
Active and Passive Immunity
develops after birth as a result of exposure to a pathogen vaccination or other means and it is developed over time
Acquired immunity
is exposed to a pathogen or vaccinated and his/her immune system recognizes the pathogen and produces antibodies and immune cells. so when the pathogen is met again the immune system will respond quickly
Active Immunity
provided to his/her through transfer of antibodies or immune cells from someone else
Passive Immunity
temporary and lasts only as long as transferred antibodies or cells remain viable
Passive Imunity
physical and chemical barriers that protect the body from pathogenic microorganisms entering the body
External Defense System
body uses to defend itself against pathogens that have entered the body by physical and chemical mechanisms such as fever inflammation and through WBCs
Internal Defense System
produced by antibodies in response to inflammation and is produced by hepatocytes
Acute Phase Reactants
reactants increase rapidly by ?% in response to inflammation and decreases rapidly once resolved
25%
defend the body against pathogens and abnormal cells including phagocytosis, cell mediated immunity and activity of NK cells
Cellular Defense Mechanism
4 main steps of phagocytosis?
Physical contact between white cell and foreign particles, Formation of phagosome, Fusion wt cytoplasmic granules to form phagolysosome, Digestion and release of cell debris
discovered by fly drosophila
Toll Like Receptors (TLR)
lipoprotein in mycobacteria
TLR1
peptidoglycan in gram + bacteria
TLR2
lipopolysaccharide in gram - bacteria
TLR3
reaction of body to injury or invasion by an infectious agent
Inflammation
major events associated with the process of inflammation?
Increased blood supply infected area, Increased capillary permeability caused by retraction of endothelial cells lining the vessels, Migration of WBC (neutrophils) from capillaries to surrounding tissue, Migration of macrophages to injured area
what WBC increases during acute bacterial infection?
Neutrophil
what WBC increases during parasitic invasion?
Eosinophil
what WBC is involved during allergic reax?
Basophil
helps produce IgE
Basophil
cytoplasm of ? is heavily granulated which stains light purple and has a lot of lobes
Neutrophil
bilobed, ellipsoidal, eccentric nucleus; large reddish-orange granules
scattered evenly in the cytoplasm
Eosinophil
has course, densely staining deep-bluish purple granules that often obscure the nucleus
Basophil
largest cell in the peripheral blood
Monocyte
arise from monocytes
Macrophage
- inflammatory cells that resemble basophils but arise from different cell
lineage - involved in allergic reactions
Mast cell
- cells that are covered with long, membranous extensions that resemble
nerve dendrites - capture antigens through phagocytosis or endocytosis then presents it to T
cells to initiate the specific immune response
Dendritic cell
movement of phagocytes towards the source of chemoattractants
Chemotaxis
movement of phagocytes from the circulating pool to the
peripheral tissues through the vessel walls
Diapedesis
first line of defense against cells that are infected with viruses and
intracellular parasites, and tumor cells
Natural Killer cells
glycoprotein with host-specific antiviral activity by inducing transcription of
genes coding for antiviral protein that selectively inhibits synthesis of viral
RNA and protein
Interferon
- Most important immune cell
- Orchestrates the immune system
- Will become immunocompromised without it
CD4+ T cell (Helper T cell)
similar with Natural killer cell, but is more antigen-specific or requires
antigen presentation for activation
CD8+ T cell (Cytotoxic T cell)
regulates immune response
Suppressor T Cell / T Regulatory Cell
when activated, they become plasma cells which are responsible for
producing antibodies
B cell
