Immunity Flashcards
(12 cards)
What is an antigen
A substance capable of stimulating the production of specific and complementary antibodies
What is an antibody
Globular proteins that are specific and complementary to particular antigens that can react with antigens leading to their destruction
What is the purpose of killer t-cells
destroy infected cells by attaching to the antigen of the surface of the infected cell and releasing the cehmical perforin, which punches holes in the cell surface membrane, leading to lysis and death of cell
What is the purpose of helper t-cells
stimulate b-cells to divide and produce plasma cells-synthesise and secrete antibodies
-attach opsonins- mark fo phagocytosis
-release interferon- hinders the viruses ability to replicate
What is the purpose of suppressor t-cells
-block b and t reponses-dampen immune response
-prevent autoimmune responses where the immune system attacks self cells
What is monoclonal antibody production
Monoclonal antibody production is the method of obtaining antibodies for medical use
-involves removing sensities and cloned b lymphocytes from a mouse which has been injected with an antigen
-b lymphocytes and hybridised with cancer cells to produce antibodies in a fermenter on a large scale over a long time period
Why is secondary responses better
-produce a more rapid response- memory cells and already activated and cloned/ no activation or clning required
-produce a high response- both b lymphocytes and memory cells are producing plasm cells
What are the strategies to reduce organ rejection
- Immunosuppression- use drusg to inhibit DNA replication, cell division and cloning of lymphocytes
-inactivate b and t cell responses- no plasma cells, memory or killer t cells produced
-delays rejection as no antibodies to attack organ
-increased risk of infection-take drusg for life - X-rays- irradiates bone amrrow and lymph tissue- to inhibit production of lymphocytes and slow down rejection
What is an epidemic
A disease that spreads rapidly through a higher proportion of the population than normal
What is a pandemic
A disease affecting many thousands of people, in several countries at the same time
Why are viruses the agents of widespread infection
-Have small genomes- prone to infection
-antibiotics not effective
Why are bats suitable resevoirs
-Have a similar physiology to humans
-fly large ranges and potentially in contact with other organisms
-social animals- in contact with large numbers of other bats- increasing possibility of cross infection
