4) Chronic Inflammation

Question 1

Define chronic inflammation?

Answer 1

Chronic response to injury with associated fibrosis

Question 2

How does chronic inflammation arise? (3)

Answer 2

1) May take over acute inflammation if damage is too severe to be resolved
2) Arise from day novo - autoimmune, chronic low level irritation
3) Develops alongside acute inflammation - in severe, persistent or repeated irritation

Question 3

Effects of chronic inflammation? (4)

Answer 3

1) Fibrosis - e.g peptic ulcers, cirrhosis
2) Impaired function - increases/reduces function
3) Atrophy e.g adrenal glands, gastric mucosa
4) Stimulate immune system response - macrophages and lymphocytes

Question 4

Types of cells involved in chronic inflammation? (6)

Answer 4

Macrophages
Lymphocytes
Plasma cells
Eosinophils
Myo/Fibroblasts
Giant cells

Question 5

Explain the functions of macrophages? (4)

Answer 5

Derived from monocytes

1) Phagocytosis and opsonisation
2) Antigen presenting cells
3) Synthesis of cytosine, complements, proteases, blood clotting factors
4) Controls other cells via cytokines

Question 6

Explain the functions of lymphocytes? (3)

Answer 6

1) Mainly immunological
2) Pass the thymus to differentiate into T lymphocytes to control cytotoxic functions
3) Can differentiate into B lymphocytes -> Plasma cells -> release Ab’s

Question 7

Explain functions on plasma cells, eosinophils, myo/fibroblasts?

Answer 7

Plasma cells - release Ab’s
Eosinophils - used in tumours, allergic reactions
Myo/fibroblasts - secrete collagen due to fibrosis and contract to hold the tissue together

Question 8

What are giant cells?

Describe 3 types of giant cells?

Answer 8

Multi nucleated cells created by fusion of macrophages via frustrated phagocytosis

1) Langhans in TB
2) Foreign body type
3) Touton in Fat necrosis

Question 9

Explain chronic cholecystitis?

Answer 9

Repeated obstruction of gall bladder with gall stones -> repeated acute inflammation -> chronic -> fibrosis of bladder wall (treatment: remove gall bladder)

Question 10

Explain gastric ulceration?

Answer 10

Imbalance of acid production and mucosal defence
Acute cause - Alcohol, drugs
Chronic cause - H. pylori (treat with antibiotics e.g amoxicillin)

Question 11

Describe 2 types of inflammatory bowel disease?

Answer 11

1) Ulcerative colitis - superficial damage to crypts, causes diarrhoea, rectal bleeding and treat with colectomy or immunosuppressive pills
2) Crohn’s disease - Transmural, strictures (narrowing), fistulas (abnormal connection between epithelia), regional enteritis (patchy throughout bowel), has granulomas
Treatment: Diet, hydration, immunosuppressants

Question 12

Describe liver cirrhosis?

Answer 12

Leads to disorganisation of architecture and attempted regeneration (nodules)
Causes: alcohol, fatty liver, drugs, toxins, hep. B/C

Question 13

Describe Grave’s disease?

Answer 13

Increased function - autoimmune antibodies stimulate TSH receptors
Treatment: Carbimazole and surgery

Question 14

Explain gastric mucosa atrophy?

Answer 14

Cells produce acid -> destroy parietal cells -> fibrosis of mucosa -> atrophy -> gastritis and impaired function
Main cells involved: lymphocytes

Question 15

Explain rheumatoid arthritis?

Answer 15

Autoimmune both localised and systemic inflammation -> leads to joint destruction
Can affect other organs and cause amyloidoses
Main cells involved: plasma cells

Question 16

Define granulamatous inflammation?
Define granuloma?
When do they arise? (2)

Answer 16

• Chronic inflammation with granulomas
• Mass of macrophages (aka epithelial histiocytes which are immobile and inactive) with associated lymphocytes
  1) Persistent, low level antigenic stimulation
  2) Hypersensitivity

Question 17

Main causes of granulomas?

Answer 17

1) Mildly irritant foreign material
2) Infections: TB, leprosy, Syphilis, cat scratch disease, chronic fungal
3) Unknown - sarcoids, Crohn’s disease, Wegener’s granulomatosis

Question 18

Describe TB?

Answer 18

Caused by mycobacterium, use Acid fast stain
Caseous necrosis with giant cells and granulomas
Produces toxins/ lytic enzymes -> induces persistent cell mediated immunity
Difficult to destroy by macrophages
Outcomes: Arrest with fibrosis, erode bronchus, erodes lung pleura, erosion leads to infection spreading into the blood stream

Question 19

Describe sarcoidosis?

Answer 19

Unknown cause - involves lymph nodes and lungs
Non-caseating granulomas and giant cells
Can lead to scarring in the lung - pulmonary fibrosis

Question 20

Main differences between chronic and acute inflammation

Answer 20

Chronic - Macrophages, heterogenous, ends with fibrosis

Acute - Neutrophils, stereotypical, can be resolved or become chronic inflammation