The immune system Flashcards
1
Q
Which white blood cells are involved in non-specific defences?
A
- Phagocytes
- e.g Macrophages, Neutrophils
2
Q
Which white blood cells are involved in specific defences?
A
- lymphocytes
- B lymphocytes, T lymphocytes
3
Q
What are Opsonins?
A
- Molecules which recognise foreign chemicals and stick to them
- Include antibodies and complement (other molecules)
4
Q
How do opsonins work?
A
- they attach to the pathogens to tag them as foreign
5
Q
Stage 1 of immune response
A
- phagocytes are attracted to molecules produced by pathogen
- receptors on phagocyte membrane attached to opsonin
- phagocyte engulfs pathogens into a phagosome
- lysosome fuses with phagosome to break down pathogen and destroy it
6
Q
Why are ** Neutrophils** different?
A
- They rapidly engulf & destroy pathogen at site of an infection
- They move towards wound in response to cytokines, released by cells at site of wound
7
Q
Why are Macrophages different?
A
- They act as an Antigen-presenting cell (APC)
- glycoproteins (MHC) move to the phagosome and bind to the antigens
- MHC-antigen complex moves to cell surface membrane of macrophage
- antigens are presented to the outside of the cells
8
Q
What is the significance of antigen presenting cells?
A
- play a critical role on specific immune system by presenting antigens to lymphocytes
9
Q
Describe role and function of Cytokines?
A
- After phagocyte engulfs pathogen it releases cytokines
- they signal to phagocytes to move to a site of infection/wound
- they trigger inflammation and fever
10
Q
A
