detecting pathogens

Question 1

pathogen

Answer 1

an agent that causes disease

Question 2

antigen

Answer 2

any molecule that can trigger an immune response. It can be a protein, sugar, DNA or RNA. They can be free floating.

Question 3

non self antigen

Answer 3

a molecule from outside the body that initiates an immune response

Question 4

MHC markers

Answer 4

self antigens located on the surface of cells - so the immune system does not attack them

Question 5

MHC 1

Answer 5

expressed on all nucleated cells in the body, and marks them as self so that they are not attacked

Question 6

MHC 11

Answer 6

expressed on antigen presenting cells, which interact with T helper cells in the process of antigen presentation.

Question 7

why can organ transplants be difficult?

Answer 7

The MHC 1 markers differ between people, so the mhc marker from the organ donor can be rejected from the organ reciever - can stimulate the reciever to recognise it as non self and launch an attack.

Question 8

autoimmune diseases

Answer 8

a disease where the immune system recognises it’s self cells as non self

Question 9

allergen

Answer 9

a non pathogenic antigen that triggers an allergic reaction

Question 10

allergic reaction

Answer 10

overreaction to the presence of an allergen

Question 11

cellular pathogens + examples

Answer 11

cellular structure, and are living : bacteria, fungi, protozoa, and parasites

Question 12

non cellular pathogens + examples

Answer 12

do not have a cellular structure and are non living : viruses and prions