Inflammation

Question 1

What are the 5 main signs on inflammation?

Answer 1

Redness, heat, swelling, pain and loss of function.

Question 2

What are the steps for inflammation?

Answer 2

Change in local blood flow, structural changes in microvascalature, recruitment of immune cells and proteins.

Question 3

2 examples of inflammatory signals when a wound occurs?

Answer 3

Non apoptotic cell death and foreign material.

Question 4

After damage to tissue occurs and inflammatory signals are released, what happens?

Answer 4

Vasodilators are released - histamines and nitric oxide.

Question 5

What do vasodilators result in?

Answer 5

Vascular changes. Increased permeability. Dilation. Plasma leakage.

Question 6

How does increased vascular permeability and leakage act as a barrier to pathogens?

Answer 6

Increased swelling. Pathogens have to travel further.

Question 7

Apart from histamines what other molecules are found at injury?

Answer 7

Prostaglandins, cytokines, chemokines and complement proteins.

Question 8

What is exudate?

Answer 8

Fluid, proteins and cells that have seeped out of a blood vessel.

Question 9

When it comes to immune cell recruitment what do chemokines do?

Answer 9

Chemokines diffuse out to form a gradient. Leukocytes expressing complementary chemokine receptors migrate towards chemokine source.

Question 10

What is neutrophil extravasation?

Answer 10

Neutrophil extravasation is the movement of neutrophils out of the circulatory system and towards the site of tissue damage or infection.

Question 11

What is the first step of neutrophil extravasation?

Answer 11

Leukocyte such as a macrophage releases cytokines that activate adhesion molecules (selectins) on endothelial surface.

Question 12

What is the second step of neutrophil extravasation?

Answer 12

Integrins in low affinity state on neutrophils bind to selectins. This is referred to as rolling adhesion.

Question 13

What is the third step of neutrophil extravasation?

Answer 13

Chemokines promote low to high affinity switch integrin switch.

Question 14

What is the fourth step of neutrophil extravasation?

Answer 14

Cytoskeletal rearrangement to migrate out of endothelium.

Question 15

How do neutrophils recognise gram negative bacteria?

Answer 15

Use their receptors to recognise lipopolysaccharide molecules on surface of gram negative bacteria.

Question 16

How do neutrophils directly clear pathogens?

Answer 16

Phagocytosis. Netosis.

Question 17

How do neutrophils indirectly clear pathogens?

Answer 17

Release cytokines which recruits and activates other immune system cells.

Question 18

Explain phagocytosis process

Answer 18

Microbe engulfed into phagosome. Phagosome fuses with lysosome to form phagolysosome. Reactive oxygen species and antimicrobial peptides kill microbe in phagolysosome.

Question 19

What do macrophages do to resolve inflammation?

Answer 19

Clear apoptotic cells. Produce anti inflammatory mediators.

Question 20

What can cause chronic inflammation?

Answer 20

Autoimmunity, prolonged infection, persistent toxic stimuli and unclearable particulates.

Question 21

What cells do you see in chronic inflammation?

Answer 21

Lymphocytes, macrophages, and plasma cells

Question 22

What repair processes occur in chronic inflammation?

Answer 22

Angiogenesis and fibrosis.

Question 23

What is the main cell in acute inflammation?

Answer 23

Neutrophils.

Question 24

What can happen when monocytes are recruited to tissue from blood?

Answer 24

They can differentiate into macrophages.

Question 25

Key macrophage features?

Answer 25

Phagocytic, cytotoxic, anti-inflammatory and involved in wound repair.

Question 26

What is granulomatous inflammation?

Answer 26

Chronic inflammation with formation of granulomas.

Question 27

Why are granulomas formed?

Answer 27

To act as a barrier. To contain an area of bacterial, viral or fungal infection so it can try to keep it from spreading.

Question 28

What causes granulomatous inflammation to form?

Answer 28

Strong T cell response.

Question 29

Characteristics of chronic inflammation?

Answer 29

Persistent inflammation, monocytes and macrophages are the dominant cell type present, ongoing cytokine release and scarring. T cells and B cells also present.

Question 30

Characteristics of acute inflammation?

Answer 30

Vasodilation, increased vascular permeability, neutrophils dominant cell type present, histamine release and necrosis.

Question 31

Consequences of long term inflammation?

Answer 31

Tissue damage, scarring, loss of function which can lead to organ failure.

Question 32

Explain what leads to swelling in inflammation?

Answer 32

Vascular leakage increases blood flow into the inflamed tissue, leading to fluid build-up.

Question 33

Explain what leads to redness in inflammation?

Answer 33

Accumulation of blood contents including red blood cells near surface of skin.

Question 34

Explain what leads to heat in inflammation?

Answer 34

Heat results from the increased presence of fluid at core body temperature at a site that would otherwise have a limited exposure to this. During inflammation infiltrating immune cells are also highly metabolically active, which may also contribute to the generation of heat as a by-product. 

Question 35

Explain what leads to pain in inflammation?

Answer 35

Inflammatory mediators signalling on local nerve cells.