Immunity Flashcards
What does non-specific immunity do?
prevents entry of microbes into the body or remove foreign material
What are the two types of immunity?
- non specific aka innate immunity
- specific resistance immunity
What are the different components of innate immunity?
1) Physical Barriers
2) Mechanical Barriers
3) Chemical Barriers
4) Normal Flora
5) Phagocytes
6) Inflammation
7) Fever
4) Natural killer Cells
What are the physical barriers of immunity?
skin and mucous membranes
What are the chemical barriers of non-specific immunity?
- gastric acid, lysozyme (in saliva + tears)
- interferons
Interferons are produced by what? What do they do?
product of virus infected cells which trigger mechanisms in nearby uninfected cells that prevent infection
What are some mechanical barriers in non-specific immunity?
flow of tears, sweat, mucus; cilia beating; coughing
What does the normal flora do?
outcompete newcomers
What are examples of phagocytes?
- macrophages and neutrophils
Macrophages are active in what type of infection?
chronic infections
Neutrophils are active in what type of infection?
short term infection
What does inflammation have to do in non-specific immunity?
- the local tissue damage release chemicals such as histamine from mast cells which causes:
- vasodilation = swelling, heat, redness and pain which causes loss of function
- attracts neutrophils (within 1 hour) and then macrophages
Where are mast cells found?
in CT; similar to basophils
What is the significance of fever in non-specific immunity?
- the immune cells and microbe chemicals trigger release of prostaglandins in hypothalamus which increases immunity.
What decreases prostaglandin synthesis?
- aspirin, ibuprofen, acetaminophen
What happens when production of prostaglandin decreases?
Fever decreases
What do natural killer cells do?
- kill cells they do not recognize
What do specific resistance immunity target?
specific pathogens
What is specific resistance immunity?
production of specific lymphocyte or antibody against a recognized antigen.
what are antigens?
- proteins/polysaccharides that are recognized as foreign by the immune system
Antigens are usually from?
- bacteria, viruses, pollen, transplant, parasites
What are antibodies?
Plasma protein (Y globulin) that matches a specific antigen
What produces Antibodies?
plasma cells
Typically what happens in an immune response?
- the phagocytes (eg. macrophage) eats invaders and exposes parts of its antigen on its surface
- the T Helper cells then binds and proliferate which release chemicals that trigger either cell mediated immunity OR humoral (antibody mediated) immunity
- memory B/T cells are also produced which are long lived and this allows a rapid response on next encounter with the same antigen
What happens in cell mediated immunity?
- an immune response that does not involve antibodies but rather the activation of phagocytes, cytotoxic T-lymphocytes and release of various cytokines
What happens in a cell mediated immunity?
- the Cytotoxic T-lymphocytes are activated (due to T helper cell proliferation) and proliferate which directly destroy cells containing viruses; cells altered by cancer; or transplant cells
what happens in a humoral (cell mediated) immunity?
- the B cells are activated (due to T Helper cell proliferation) and convert to plasma cells which create antibodies
What are the different types of Humoral Immunity?
Active and passive immunity
What is an Active Humoral Immunity?
- when body makes antibody, memory B cells after exposure to disease org = natural or injection with killed/inactivated disease org(vaccination, artificial)
What is a Passive Humoral Immunity?
- it lasts weeks as long as antibody is present
- can be natural: mother via fetus across placenta and milk can pass immunity
- can be artificial: artificially produced Antibodies (from person, animal, monoclonal). They are injected for tetanus, rabies, snake bite antivenins, Rh factor. They mop up the antigen before it can even trigger an immune response
