non-specific defences (internal)

Question 1

when are the internal defences used?

Answer 1

• bodys second line of defense

- when pathogens get through external defences

Question 2

what are phagocytes?

Answer 2

• type of leucocytes
• engulf & digest micro-organism & cell debris
• eliminate pathogens before infection can take place
• easily pass through blood capillary walls into surrounding tissue towards pathogens

Question 3

describe the process of phagocytosis

Answer 3

1) phagocyte moves to the bacterium
2) phagocyte changes shape so it completely encloses bacterium
3) lysosome contain destructive enzymes
4) enzymes are released and destroy the bacterium
5) harmless particles are released from phagocyte

Question 4

what are the 2 things phagocytes do?

Answer 4

1) secrete substances that destroy bacteria before engulfing them
2) engulf live bacteria and digest them with digestive enzymes (break down)

Question 5

what are monocytes?

Answer 5

= leave the bloodstream and enter inflamed tissue

- differentiate into macrophages

Question 6

what are macrophages?

Answer 6

large phagocytic cells move through looking to destroy pathogens, remove microbes & dying cells

Question 7

what are neutrophils?

Answer 7

• granulated leucocyte

- first cells move into the tissue to destroy

Question 8

what are the 3 types of cells that are phagocytic?

Answer 8

monocytes
neutrophils
dendritic cells

Question 9

what are dendritic cells?

Answer 9

• characterized by projections from the cytoplasm
• detect, engulf and process foreign particles
• use the info to assist with specific immunity