cell recognition and the immune system

Question 1

what is a phagocyte?

Answer 1

type of white blood cell

Question 2

what are non-specific defense responses?

Answer 2

stomach acid
skin
tears
phagocyte

Question 3

what is an antigen?

Answer 3

foreign body that can stimulate an immune response

Question 4

how does phagocytosis work?

Answer 4

• phagocyte detects pathogen
• phagocyte engulfs pathogen to form a phagosome
• phagosome fuses with lysosome and lysozymes hydrolyse the pathogen
• the phagocyte absorbs the products from the hydrolysis of the pathogen
• antigens are presented on its surface

Question 4

two types of specific immune response

Answer 4

cell mediated
humoral

Question 5

what is an antibody?

Answer 5

a protein that binds to an antigen
produced by the bodys b cells

Question 6

what is a vaccination?

Answer 6

injecting a dead/weakened pathogen to stimulate an immune response and provide immunity by the body producing memory cells

Question 7

how does HIV replicate?

Question 8

what is the role of antigen presenting cells?

Answer 8

wgh

Question 9

what are the differences between specific and non-specific responses?

Answer 9

specific - b/t lymphocytes , complementary to the pathogen , slow

non specific - phagocytosis , same for all pathogens , immediate

Question 10

what are memory cells?

Answer 10

specialised helperT/B cells that remian in the blood

Question 11

outline the cellular response

Answer 11

• antigen on the antigen presenting cell and receptor on T cell bind
• this activates the t-cell
• t-cell rapidly divides by mitosis
• differentiate into
  – cytotoxicTcells which releases a protein that ‘punches’ a hole in the membrane
  – helperTcells which activate B cells