Session 3 - Chronic Inflammation

Question 1

What does chronic inflammation look like?

Answer 1

• Microscopically as mononuclear cells (macrophages and lymphocytes most commonly)
• Granulation tissue

Question 2

How are macrophages involved in chronic inflammation?

Answer 2

• Phagocytosis
• Secrete numerous substances that attract other cells to area
• antigen-presenting cells
• angiogenesis
• induces fibrosis and fever

Question 3

How are T+B lymphocytes involved in chronic inflammation?

Answer 3

• processing antigens
• secreting antibodies
• secreting cytokines
• Killing cells

Question 4

How are eosinophils involved in chronic inflammation?

Answer 4

• Attack large parasites (worms)

- Will be present in larger numbers in particular cases, eg in the bronchi in asthmatic patients and in some tumours

Question 5

What are the roles of fibroblasts and Myofibroblasts in chronic inflammation?

Answer 5

• Fibroblasts secrete CT substances like collagen and elastin
• Myofibroblasts involved in contractile mechanisms that can decrease the size of the site of damage

Question 6

What are Giant Cells?

Answer 6

Very large cells that have formed through the fusion of many macrophages.
They can contain up to 100 nuclei and are seen in granulation tissue

Question 7

Name the three types of Giant Cell

Answer 7

• Langhans Giant cell
• Foreign Body Giant cell
• Touton Giant cell

Question 8

When may we see Langhans Giant cell and how are the nuclei arranged?

Answer 8

• Often seen in TB

- Nuclei arranged around the periphery of the cell

Question 9

When might we see Foreign Body Giant cells and how are nuclei arranged?

Answer 9

• Seen when there is hard to digest material present (like some plastic), the material may be on the inside of the Giant cell
• Nuclei are randomly arranged

Question 10

When might we see Touton Giant cells and how are the nuclei arranged?

Answer 10

• Seen in fat necrosis + xanthoma

- Nuclei are arranged in a ring towards the centre of the cell

Question 11

What is fibrosis?

Answer 11

Excess fibrous tissue

Question 12

How does fibrosis occur and how can it cause damage?

Answer 12

Fibroblasts secrete too much collagen and in excess this can replace normal parenchymal tissue or even impair function

It also contains myofibroblasts which can cause damage because as they contract they can cut off the blood supply

Question 13

How can chronic inflammation be involved in innapropiate immune responses and give an example?

Answer 13

• Immune system may bind to an innocuous targets, triggering inflammation
• Examples include pollen or bodies normal tissue in rheumatoid arthritis

Question 14

When will granulomatous tissue be present?

Answer 14

When there are materials that are poorly soluble or difficult to eliminate

Question 15

What are epitheloid cells?

Answer 15

Flattened macrophages that look like epithelial cells that are present in granulomatous inflammation

Question 16

What happens in foreign body granulomas?

Answer 16

• Macrophages, foreign body Giant cells, epitheloid cells and some fibroblasts all present
• develops around a material that is not antigenic

Question 17

What happens in Hypersensitivity/immune type granulomas?

Answer 17

• contains Macrophages, Giant cells, epitheloid cells, some fibroblasts and lymphocytes
• develop around insoluble but antigenic material
• Can be harmful as they occupy parenchymal space within organ

Question 18

Which three ways can chronic inflammation arise?

Answer 18

1- By taking over from acute inflammation (most common)

2- Can begin de novo

3- May develop alongside acute inflammation (ongoing bacterial infection)