Phagocytosis

Question 1

What do cells release when they are under attack?

Answer 1

Histamines

Question 2

What is the process of phagocytosis?

Answer 2

• Phagocyte wraps pseudopodia around the microbe, engulfing if
• This forms a vesicle (phagosome)
• Phagosome fuses with a lysosome to form a phagolysosome
• Lysozomes then break down the microbe

Question 3

How does the immune response fight infection?

Answer 3

• Releases histamine to attract phagocytes
• Monocytes travel in the blood to move into tissues
• Develop into macrophages and then settle in organs
• They then initiate an immune response via antigen presentation

Question 4

What are the 2 types of phagocyte?

Answer 4

Neutrophils:
- Large lobed nucleus
- Can squeeze into tissues
- Patrol blood and engulf bacteria agglutinated by antibodies
Macrophages:
- Settle in tissues and organs
- ‘Rubbish collectors’
- Foreign antigens embedded in membrane
- Antigen presenting