MOD 3.1 - Chronic Inflammation Flashcards
Give three ways in which chronic inflammation can arise
- Permanent tissue damage/ damage not resolved within a few days
- Can arise out of nowhere e.g. Autoimmune conditions or chronic infections
- Can happen alongside acute inflammation i.e. It’s severely persistent/repeated
What does chronic inflammation look like?
- Very diverse so need to look at microscopic appearance
- Type of cell present is most important
Which cells are most associated with chronic inflammation? Give two details about them
- Macrophages
- Lots of granular cytoplasm
- Big, digest foreign material
What do macrophages derive from?
Blood monocytes - have varying levels of activation
Give three functions of macrophages
- Good at phagocytosis
- Picking up and presenting of antigens
- Synthesis of molecules
Give four molecules that are synthesised by macrophages
- Cytokines
- Complements
- Proteases
- Clotting factors
What do lymphocytes look like under the microscope?
- Lots of blue dots
- Large, round nucleus
What is the function of lymphocytes?
Differentiate into:
- B-lymphocytes (plasma cells) - antibody production
- T-Lymphocytes - control and cytotoxic functions
What do Eosinophils look like under the microscope?
Bright pink circles with a bilobed nucleus
What are the functions of Eosinophils? (3)
Mediation in response to:
- Allergic reactions
- Parasite infections
- Some tumours
What is the function of a fibroblast?
Production of collagen after being recruited by macrophages
What is a giant cell?
Multinucleate cell made by the fusion of macrophages due to frustrated phagocytosis
When are giant cells formed?
When one macrophage cannot easily phagocytose the foreign material
What are the three types of giant cell and where can they be found?
- Langhans (tuberculosis)
- Foreign body type
- Touton (Fat necrosis)
Describe the appearance of a Langhans giant cell
Horseshoe of nuclei
Describe the appearance of a foreign body type giant cell
- Disorganised
- Many little groups of nuclei
Describe the appearance of Touton giant cells
- Horseshoe/circle of nuclei
- Foamy outside of cell
Describe the morphology of chronic inflammation
Mostly non specific
Which condition causes tissue to become rich in plasma cells?
Rheumatoid arthritis
Which condition causes tissue to become rich in mainly lymphocytes
Chronic gastritis
Which condition causes tissue to become rich in mainly macrophages?
Leishmaniasis
Give the effects of chronic inflammation (4)
- Fibrosis
- Impaired function
- Atrophy
- Stimulation of immune response
How is scar tissue (fibrosis) formed due to chronic inflammation?
Happens due to multiple episodes of acute inflammation
Describe the occurrence of cirrhosis
- Fibrosis and impaired function
- Disorganisation of architecture and attempted regeneration
Give two conditions of chronic inflammation where fibrosis results
- Cholecystitis (swelling of gallbladder due to blockage of cystic duct)
- Peptic ulcers
Why do peptic ulcers form?
Form due to an imbalance of acid production and mucosal defence
Give an example of a condition where chronic inflammation has caused impaired function
Inflammatory bowel disease e.g. Ulcerative colitis or Crohn’s disease
What is the difference between ulcerative colitis and Crohn’s disease?
UC = superficial, crypt abscesses and distorted crypt architecture common
C = Transmural, Fistulae and strictures
What is a fistula?
An abnormal connection between two epithelium-lined organs
What is a stricture?
The narrowing of a tubular structure
What is atrophy? Give an example of atrophy that has arisen due to chronic inflammation
- Loss of functional tissue
- Atrophic gastritis = loss of gastric mucosa
Give an example of a condition that arises due to the stimulation of the immune system as a result of chronic inflammation
- Rheumatoid arthritis (can be localised or systemic)
How do localised and systemic rheumatoid arthritis differ?
- Localised = destruction of joints
- Systemic = Other organs are affected and can cause amyloidoses
What is granulomatous inflammation?
Chronic inflammation with granulomas
What is a granuloma?
A cohesive group of macrophages and other immune cells
When does granulomatous inflammation arise?
- Hypersensitivity reactions
- Persistent low grade antigenic stimulation
What are the causes of granulomatous inflammation? (3)
- Mildly irritant foreign material
- Infections e.g. Mycobacteria and some fungi
- Unknown e.g. Crohn’s disease, Sarcoidosis
What are the effects of an infection with mycobacterium tuberculosis? (4)
- Fibrosis
- Erosion in bronchioles
- Empyema
- Erosion in blood
What is the definition of chronic inflammation?
The chronic response to injury with associated fibrosis
What is a foreign body granuloma?
- Granuloma that contains:
- Macrophages
- Giant cells
- Foreign body
- Epithelioid cells
- Some peripheral fibroblasts
- Very few lymphocytes
What are the cell types in a hypersensitivity/immune granuloma?
- Macrophages
- Giant cells (usually langhans)
- Epithelioid cells (more prominent)
- Fibroblasts
- Lymphocytes
Give a property of hypersenstivity granulatomas. Where can they normally be found?
- Can undergo central necrosis
- Granulatomas associated with tuberculosis
