12.5 The immune system + Phagocytosis

Question 1

what is an antigen?

Answer 1

a protein found on the surface of cells

Question 2

how does the immune system recognise pathogens as foreign?

Answer 2

their antigens are identified as foreign which leads to an immune response

Question 3

what are the two types of lymphocyte?

Answer 3

B and T

Question 4

where are B lymphocytes produced from?

Answer 4

the bone marrow

Question 5

where are the T lymphocytes produced from?

Answer 5

the Thymus gland

Question 6

types of T lymphocytes

Answer 6

T helper
T killer
T memory
T regualator

Question 7

T helper

Answer 7

bind to the antigen on an APC
stimulates production of interleukins which stimulates B cells

Question 8

T killer

Answer 8

produce perforin which kills the pathogen by making holes in the cell surface membrane
destroys pathogens

Question 9

T memory

Answer 9

form a part of the immunological memory by retaining the information on a foreign antigen
when the antigen is detected again, it divides to form T killer cells to destroy the pathogen

Question 10

T regulator

Answer 10

suppress the immune system in order to control and regulate it

prevents an autoimmune response fromoccuring

Question 11

what is an autoimmune response?

Answer 11

when the immune system attacks self cells

Question 12

types of B lymphocytes

Answer 12

plasma cells
B effector
B memory

Question 13

plasma cells

Answer 13

produce antibodies which are specific to an antigen

Question 14

B effector

Answer 14

divide to form clones of plasma cells

Question 15

B memory

Answer 15

provide immunological memory by remembering a specific antigen and when it encounters it again it divides into plasma cells

Question 16

step 1 immune response
phagocytosis

Answer 16

phagocyte recognises the antigens on pathogen
opsonins bind to the antigens on the pathogen to make phagocytosis easier
phagocyte surrounds the pathogen and engulfs it to form a phagosome
lysosomes fuse with the phagosome to form a phagolysosome which breaks down the pathogen
the antigens on the pathogen are then presented on the phagocyte to form an APC

Question 17

step 2 immune response
T lymphocyte activation

Answer 17

T helper cells bind to antigens on the APC which causes them to activate
the activation of T helper cells leads to clones of itself being formed
these clones:
- become T memory cells
- become T killer cells
- produce interleukins to stimulate B cells

Question 18

step 3 immune response
B lymphocyte activation

Answer 18

activated B cells divide by mitosis to produce clones of plasma and B memory cells
plasma cells produce antibodies which are specific to the antigen on the APC
the antibodies then deal with the pathogen
if the body is infected again the B memory cells divide by mitosis into plasma cell clones which produce more of the specific antibody

Question 19

how does an autoimmune disease work?

Answer 19

recognises the antigens on self cells as foreign
leads to the production of antibodies specific to these antigens
phagocytosis of self cells occurs

Question 20

what is the immune response?

Answer 20

response to an antigen which involves the production of antibodies