2nd Line Defence

Question 0

How are complement proteins identified

Answer 0

With a letter and number - C3

Question 1

What is complement system

Answer 1

System made of over 30 proteins produced by liver and found circulating round body

Question 2

How do these proteins act when activated

Answer 2

In a cascade to ‘complement’ immune processes

Question 3

Collectively, complement proteins destroy microbes and promote immunity by

Answer 3

Promoting phagocytosis & inflammation

Causing cytolysis -destroying (bursting) microbes

Question 4

3 ways compliment system may be activated

Answer 4

Classical pathway
Alternative pathway
Lect in pathway

Question 5

Describe classical pathway

Answer 5

Activation of compliment system when antigen-antibody complexes are formed

Question 6

Alternative pathway - describe

Answer 6

Direct activation of complement by lipid-carbohydrate markers already on invading cells surface
(Pathogen surface markers)

Question 7

Describe lectin pathway

Answer 7

Macrophages digest microbes, releasing chemicals that cause the LECTIN production by the liver, which help to activate the complement.

Question 8

Compliment system 4 methods of action

Answer 8

OPSONIZATION - invaders tagged for phagocytosis
Attract MACROPHAGES
Stimulate MAST CELLS to release HISTAMINE to promote INFLAMMATION
initiate CYTOLYSIS - produce membrane attack complex

Question 9

Describe cytolysis

Answer 9

Final 5 proteins in compliment cascade attach to plasma membrane of invading microbe
They form a membrane-attack complex (MAC) which inserts into the plasma membrane forming a channel
Extracellular fluid flows into invading microbe through the new channel, it swells and bursts