Inflammatory Process

Question 1

1. What is inflammation?
2. What causes it?
3. What is it for?

Answer 1

1. Inflammation is the tissue response to damage or an external invasion
2. Usually caused by any form of physical injury (incl heat or cold), hormonal changes, or autoimmune activity (e.g. RA).
3. The purpose of inflammation is to protect from pathogens, limit contamination and prepare damaged tissues for healing.

Question 2

Explain why when you scratch your skin you get a white wheal followed immediately by a red mark.

Answer 2

Vasoconstriction (to reduce blood loss) followed by vasodilation

Question 3

How and why do blood vessels dilate to form a red wheal in inflammation?

Answer 3

Damaged endothelial and mast cells release molecules that increase permeability of blood vessel walls, dilate capillaries, attract blood platelets and slow blood flow away from the area.

Question 4

1. What are the four cardinal signs of inflammation?

2. Why do they arise?

Answer 4

1. Redness, swelling, heat and pain
2. BVs dilate and become more leaky bringing more blood to the area (redness and heat), leaking more blood plasma into the tissues (swelling) and molecules that irritate nerve endings (pain).

Question 5

What are the main types of cell involved in inflammation?

Answer 5

1. Platelets
2. white blood cells
3. Fibroblasts

Question 6

Name 5 types of white blood cells

Answer 6

1. Granulocytes
2. Mast cells
3. Monocytes
4. Macrophages
5. Lymphocytes

Question 7

What are the 3 stages of healing?
What is the main feature of each stage?
How long does each stage last?

Answer 7

1. Acute: vasoconstriction/dilation & swelling. Blisters and pus (1-3days)
2. Subacute: damaged tissue is replaced by new capillaries, granulation tissue and collagen fibres. White blood cells clear up debris (2-3weeks).
3. Postacute: Collagen remodelled and reshaped and aligns according to forces placed on it.