Memory Lymphocytes And Immunisation

Question 1

what is the response to a pathogen entering the body which is new and why

Answer 1

• the response is slow

- because there arent many b- lymphocytes that can make the antibody that locks on the antigen

Question 2

what happens after someone has been infected by a new pathogen

Answer 2

• the body will produce enough of the right antibody to overcome the infection
• meanwhile, the infected person will show symptoms of the disease

Question 3

what other than antibodies are produced in response to an antigen

Answer 3

memory lymphocytes

Question 4

what do memory lymphocytes do

Answer 4

• they remain in the body for a long time

- and remember the specific antigen

Question 5

what is the result of someone producing memory lymphocytes for a specific antigen

Answer 5

• the person is now immune

- because the immune system can now quickly identify the antigen and have a quicker response

Question 6

what happens if the same pathogen enters the body again

Answer 6

• there are more cells who will recognise it and produce antibodies against it
• the secondary immune response is quicker and stronger

Question 7

what does the secondary immune response often do compared to the first immune response

Answer 7

it gets rid of the pathogen before you show any symptoms

Question 8

what can people do to prevent getting ill

Answer 8

you can be immunised against some diseases

Question 9

what does immunisation usually involve

Answer 9

injecting dead or inactive pathogens into the body

Question 10

why does immunisation work

Answer 10

• because the injected pathogen is antigenic (they carry antigens)
• so your body still produces antibodies for them even though they are harmless

Question 11

what do antigens also trigger

Answer 11

lymphocytes to be made

Question 12

what would the response of a pathogen entering the body for which someone has already been immunised against

Answer 12

• memory lymphocytes already have antigens for that specific antigen
• so the secondary immune response is alot quicker an stronger
• this means that you will be less likely to show symptoms of the disease and be infected

Question 13

how does immunisation prevent out breaks

Answer 13

• they can be prevented if a large population of the people are immunised
• even people who arent immunised are less likely to catch the disease
• because there are less people to catch it and pass it on
• this is known as herd immunity

Question 14

what is a huge advanatage of immunisation which we have evidence for

Answer 14

• it can virtually wipe out diseases

- as smallpox has virtually been wiped out due to immunisatio programmes

Question 15

what are the two disadvantages of immunisations

Answer 15

• it doesnt always work so you might not be immunised to the disease
• some people have bad reactions to immunisations which can lead to swelling or seizures (but this is very rare)

Question 16

describe how the response of the immune system changes before and after exposure to a pathogen on a graph with concentration of the right body antigen in the blood on the y axis and time on the x axis

Answer 16

• at the beginning the concentration of right antigens is nearly 0
• during the first infection, the concentration of antigens in the blood slowly increases
• and drops slowly when the infection is cleared
• the normal concentration of the right antigen is now slightly increased
• during the second infection, the concentration of the antigen rapidly increases