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Flashcards in Innate Immunity Deck (25)
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0
Q

Name two professional phagocytes of the body

A

Neutrophils and macrophages

1
Q

Name two of the body’s anti-bacterial molecules

A

Defensins and lysozyme

2
Q

How are phagocytes activated? (3)

A

By toll-like receptors

By complement proteins (C3a and C5a)

3
Q

Name two opsonins

A

C-reactive protein

C3b

4
Q

What is the membrane attack complex initiated by?

What is it?

A

C9 molecules are assembled by C5b, C6, C7 and C8 to create a hole in the microbial membrane

5
Q

What secretes sebum?

What does it contain?

A

Sebaceous glands secrete sebum

Contains acids and defensins (disrupts bacterial membranes)

6
Q

How do phagocytes recognise bacteria? Eg?

A

By pattern recognition receptors (recognise patterns commonly found on microbes)
Eg toll-like receptors

7
Q

Activated phagocytes have-

A

Increased metabolic rate
Show enhanced abilities to seek out and kill micro-organisms
Secrete cytokines

8
Q

What do complement proteins C3a and C5a do?

A

Activate phagocytes and attract inflam cells by chemo taxis and de granulate mast cells

9
Q

Which cells respond instantly to threat? And how?

A

Mast cells
Already in tissues
By degranulation

10
Q

What do mast cell granules contain?

A

Histamine, prostaglandins and chemo tactic factors for eosinophils and neutrophils

11
Q

Name 5 triggers for mast cell degranulation

A
Trauma
Hot/cold
Some chemicals 
Activated C3a and C5a
Various cytokines
12
Q

How is the growth of yeasts and other bacteria restricted in the urinary tract?

A

By friendly bacteria producing lactic acid and proponoic acid to lower pH

13
Q

4 steps in phagocytosis

A

Recognition, adherence, engulfment, destruction

14
Q

What are interferons?

A

Natural antiviral agents that act internally to protect the infected cell
Also is secreted and interacts with receptors on neighbouring cells

15
Q

Histamine causes

A

Vasodilation
Increased capillary permeability
Pain
Contraction of smooth muscle

16
Q

What do activated mast cells secrete?

A
Preformed mediators (histamine, proteases, cytokines, serotonin, heparin)
Prostaglandins, leukotrienes, platelet activation factor, eiosinophil chemotactic factor
17
Q

What do prostaglandins do?

A

Vasodilation, platelet aggregation, pain

18
Q

How do natural killer cells recognise ‘self’?

A
Using MHC class 1 
Cancerous and virally infected cells won't express it
19
Q

What does MHC stand for?

A

Major histocompatibility complex

20
Q

Where are MHC 1 and 2 found?

A

1- all nucleated cells

2- immune system cells

21
Q

Why are MHC 1 antigens important?

A

They define ‘self’
Many different genes and combinations
Donor organs need to match as many MHC molecules as poss to avoid rejection

22
Q

How do natural killer cells kill abnormal cells?

A

By releasing PERFORIN which perforates target cell membrane

23
Q

How to eosinophils kill?

A

By respiratory burst O2 and release of toxic proteins

24
Q

What do eosinophils kill?

A

Large parasites (helminths) that are too big to be phagocytosed