Immune system

Question 1

What is the innate immune system?

Answer 1

components at the location of the infection that respond immediately with a generalised response

Question 2

What is the specific immune system?

Answer 2

T&B cells that wait away from the site of infection and respond slower but with a specialised approach

Question 3

What is the first barrier to pathogens?

Answer 3

Physical: the skin and mucosa of the respiratory system, gastrointestinal tract and urinary tract
Chemical: HCl in the stomach, lysozyme in sweat and tears, and lactic acid in the vagina

Question 4

Initial immune response

Answer 4

• macrophage recognises pathogen and activates innate system
• Dendritic cells pick up antigens, track down B & T cells and activate the specific system
• activate the complement system via the lectin and alternate pathways

Question 5

How do macrophages work?

Answer 5

They identify pathogen associated molecular patterns (PAMPs) present on pathogens but not regular cells, using many receptors including toll-like receptors.

Question 6

How does phagocytosis work?

Answer 6

1. cell membrane wraps around pathogen
2. pathogen is left in a phagosome
3. lysosomes fuse with phagosome where digestive enzymes break down, destroy and process the components into harmless waste products

Question 7

What happens if a pathogen is too great for macrophages?

Answer 7

cytokines are released, triggering inflammation which recruits macrophages, monocytes and neutrophils

Question 8

What are monocytes?

Answer 8

immature versions of macrophages that float in the blood and then mature in tissues to form macrophages