immunity Flashcards

Question

how do antibodies provide resistance to infection?

Answer 1

Combine pathogen with foreign enzymes or bacterial toxins, or inactivate them by inhibiting reaction with other cells/compounds Bind them to the surface of viruses and prevent the virus from entering cells coat bacteria so they’re more easily consumed by phagocytes Cause foreign particles to clump together - agglutination Dissolving them React with soluble substances to make them insoluble and more easily consumed by phagocytes

Answer 2

the immune reaction's response upon encountering a new foreign antigen for the first time

Answer 3

It may take several days to build up large amounts of antibodies It takes time for the B cells to multiple/differentiate into plasma cells However, the primary response leaves the immune system with a memory of that particular antigen With a second exposure to the same antigen the response is much faster because of the memory cells With this secondary response plasma cells are able to form very quickly, with antibody levels in plasma rising rapidly Often the antigen has little opportunity to exert symptoms on the body

Answer 4

Provides resistance to the intracellular phase of bacterial and viral infections Important in providing resistance to fungi parasites rejects transplants of foreign tissue Also important in fighting cancer cells

Answer 5

T lymphocytes are responsible for cellular immunity, but the cells start the same way as antibody mediated A macrophage or B cell encounters the foreign antigen, travels to the nearest lymph node and presents it to the T cells The antigen activates one particular type of T cell to become sensitized It enlarges and divides, forming a clone Some cells of the clone remain in the lymphoid tissue as memory cells If infection with the same antigen should occur again, these memory cells can initiate a much faster response in the second infection

Answer 6

(T cells that don’t become memory cells develop further into 3 different types of cells) killer T cells helper T cells suppressor T cells

Answer 7

migrate to site of infection and deal with invading antigen They attach themselves to invading cells and secrete and inject a substance that will destroy the antigen, then go of in search of more antigens

Answer 8

Bring more lymphocytes at the infected site to become sensitized, thus intensifying the response Attract macrophages to the place of infection so macrophages can destroy pathogens by phagocytosis Intensify phagocytic activity of macrophages

Answer 9

Act when immune activity becomes excessive of when infection has been successfully dealt with Release substances that inhibit B and T cell activity, slowing down immune response

Answer 10

The person naturally acquires the antigen in normal everyday life, and the body responds by creating antibodies e.g. being exposed to a cold

Answer 11

The person naturally acquires the antibodies through normal life actions e.g. antibodies transferred to a baby through the placenta or breast milk

Answer 12

Someone artificially acquires the antigen, and the body responds by creating antibodies e.g. COVID vaccinations

Answer 13

Artificially acquiring the antibodies e.g. vaccination

Answer 14

Vaccinating a large enough proportion of the population to stop the transmission of a pathogen It stops the chain of transmission and does not give the pathogen a host so it can die out

Answer 15

These contain weakened micro-organisms (reduced virulence – ability to produce disease symptoms)

Answer 16

If a bacteria or virus produces a toxin, the toxin can be filtered and used as the antigen in a vaccine to initiate an immune response

Answer 17

Instead of using the whole pathogen, a fragment of the micro-organism is used to provoke and immune response

Answer 18

Using recombinant DNA - bacterial or viral DNA can be manipulated to become harmless

Answer 19

* Injections: using a syringe into the body * Oral: a syrup that is swallowed * Aerosol spray: nasal spray

Answer 20

``` redness swelling heat pain fevers ```

Answer 21

Allergic reaction: generally not from the vaccine but the medium they are cultured in (e.g. egg-white) Cross species disease: not from the vaccine but the medium that are cultured in (e.g. animal tissues) Use of chemical preservatives: concerns about health risks of chemicals, also misinformation

Answer 22

As viruses reproduce in living cells, vaccines require a host to be developed. Chicken embryos or mice use used to culture vaccines – animal welfare is an ethical consideration Sometimes human tissue needs to be used, so cells created in the IVF process are used – ethically, many people are unhappy with the origin of these cells

Answer 23

People who volunteer for drug trials need to be well informed of the risks. Often volunteers come from poorly developed nations with less education, so there is concern that they may not understand the risks adequately Before clinical trials, drugs are tested on animals

Answer 24

Parents are making decisions on behalf of their children – but a risk of a side effect may affect a child for life? Is it the responsibility of the healthy majority to become immunized to protect the vulnerable?

Answer 25

A substance that kills or inhibits the growth of bacteria E.g. penicillin, streptomycin, cephalosporin Can be broad spectrum (kills a wide range of bacteria) Can be narrow spectrum (targets specific types of bacteria) Bacteriostatic antibiotics inhibit growth of bacteria by interfering with protein synthesis Bactericidal antibiotics destroy bacterial pathogens by targeting cell walls, cell membranes or metabolic pathways/action of enzymes found inside bacteria

Answer 26

Scientists are attempting to find viral proteins that can be disabled Any drug that interferes with the replication process is likely to be toxic to the host cell There are many antiviral drugs available and more being developed