5. Chronic Inflammation

Question 1

What is the definition of chronic inflammation?

Answer 1

Chronic response to injury with associated fibrosis

Question 2

In what 3 ways can chronic inflammation arise?

Answer 2

Take over from acute inflammation - if inflammatory stimulus persists and damage is too severe to be resolved within a few days.
De novo - autoimmune conditions, chronic infections, chronic low-level irritation.
Alongside acute inflammation - severe persistent or repeated irritation eg ongoing bacterial infection.

Question 3

What is the most important characteristic in chronic inflammation?

Answer 3

Type of cell present

Question 4

What are macrophages derived from?

Answer 4

Blood monocytes

Question 5

Name 4 functions of macrophages

Answer 5

Phagocytosis
Presentation of antigens to immune system
Synthesis of cytokines, complement component,s blood clotting factors, proteases
Control of other cells by cytokine release

Question 6

What is the function of B lymphocytes?

Answer 6

Differentiate to produce antibodies

Question 7

What is the function of T lymphocytes?

Answer 7

Control and some cytotoxic function

Question 8

Where are lymphocytes found?

Answer 8

Are a normal component of many tissues, and found in chronic inflammation

Question 9

Name 2 functions of eosinophils

Answer 9

Present in high numbers in allergic reactions

Attack parasite infestations

Question 10

How are fibroblasts recruited?

Answer 10

By macrophages - respond to chemotactic stimuli

Question 11

What are plasma cells? When are they present?

Answer 11

Differentiated antibody producing B lymphocytes.

Present in severely chronic inflammation.

Question 12

What are giant cells?

Answer 12

Multinucleate cells made by fusion of macrophages

Question 13

When do giant cells form?

Answer 13

Frustrated phagocytosis - macrophages cannot phagocytose the debris/bacteria and so fuse together to form giant cells

Question 14

In what type of chronic inflammation are giant cells found?

Answer 14

Granulomatous inflammation

Question 15

What are the 3 types of giant cells? How are the nuclei arranged in each, and give an example of when they occur

Answer 15

Langhans giant cells - nuclei around periphery of giant cell, necrosis in centre. Eg TB.
Foreign body giant cells - nuclei random. Eg foreign body that is difficult to phagocytose.
Touton giant cells - nuclei in ring towards centre. Eg lesions with high lipid content such as fat necrosis.

Question 16

Name 4 effects of chronic inflammation

Answer 16

Fibrosis
Impaired function
Atrophy
Stimulation of immune response

Question 17

How does chronic cholecystitis lead to chronic inflammation and therefore fibrosis?

Answer 17

Repeated obstruction by gallstones, repeated acute inflammation, chronic inflammation, fibrosis

Question 18

How many layers of the bowel does ulcerative colitis affect? Therefore what are the main symptoms?

Answer 18

Superficial

Diarrhoea, bleeding

Question 19

How many layers does Crohn’s disease affect? What are the main symptoms?

Answer 19

Transmural (every layer)

Strictures (fibrous narrowing) and fistulae (abnormal connection between two epithelium-lined organs)

Question 20

What causes cirrhosis?

Answer 20

Chronic inflammation with fibrosis causes disorganisation of architecture and attempted reorganisation, leading to cirrhosis

Question 21

Name 3 causes of cirrhosis?

Answer 21

Alcohol
Hep B or C infection
Fatty liver disease (causes by excessive alcohol intake, diabetes, obesity)

Question 22

What is Graves’ disease?

Answer 22

Autoimmune disease, where chronic inflammation leads to increased thyroid function

Question 23

Where can chronic inflammation lead to atrophy?

Answer 23

Gastric mucosa

Question 24

What do granulomas arise with?

Answer 24

Persistant low grade antigenic stimulation or hypersensitivity. This can be severe acute inflammation, de novo chronic inflammation, or repeated attacks of acute inflammation

Question 25

Why does TB lead to granulomatous inflammation?

Answer 25

Mycobacterium produces no toxins or lyric enzymes, so is really heard to kill

Question 26

What type of inflammation occurs in Crohn’s disease?

Answer 26

Granulomatous inflammation

Question 27

What does granulomatous inflammation contain?

Answer 27

Lymphocytes and epithelioid histocytes (immobile macrophages), macrophages can clump to form giant cells