phagocytosis

Question 1

what type of response is phagocytosis and why?

Answer 1

• non specific
• same response for all pathogens

Question 2

briefly describe phagocytosis?

Answer 2

phagocytes (macrophages and neutrophils) travel in the blood and squeeze out of capillaries to engulf and digest pathogens

Question 3

stage 1 (cytokines)

Answer 3

damaged cells and pathogens release cytokines which attract phagocytes to the site of infection

Question 4

what are cytokines?

Answer 4

cell signalling chemicals

Question 5

stage 2 (opsonins)

Answer 5

opsonin proteins attach to pathogens to mark them which makes it easier for phagocytes to engulf them

Question 6

stage 3 (receptors)

Answer 6

phagocyte receptors attach to chemicals on pathogen surface

Question 7

stage 4 (engulf)

Answer 7

phagocyte engulfs pathogen into a vesicle, forming a phagosome

Question 8

stage 5 (lysosome)

Answer 8

lysosomes containing lysozyme fuse with phagosome and hydrolyse the pathogen

Question 9

stage 6 (absorb)

Answer 9

phagocyte cytoplasm absorbs any useful soluble molecules

Question 10

stage 7 (APC)

Answer 10

phagocytes present pathogen antigens on the surface, becoming an antigen presenting cell