Chronic Inflammation Flashcards
How do we progress from acute to chronic inflammation
If agent causing acute is not removed
How does acute -> chronic happen
Alongside organisation
1. lymphocytes, plasma cells and macrophages replace neutrophil polymorphs
What are the systemic effects of inflammation
Pyrexia
Weight Loss
Reactive hyperplasia of reticuloendothelial system
Haematological changes
Amyloidosis (deposition of amyloid in various tissues)
How is pyrexia caused
Polymorphs and macrophages produce endogenous pyrogens which act on hypothalamus to set the thermoregulatory mechanisms at a higher temperature
Name an endogenous pyrogen
IL-2
Why does inflammation cause weight loss
Due to negative nitrogen balance
Define hyperplasia
Enlargement of organ or tissue due to increased proliferation
Describe three haematological changes caused by inflammation
Leucocytosis
Anaemia
Increased erythrocyte sedimentation rate
What are the main causes of chronic inflammation
- Transplant rejection
- Progression from acute
- Recurrent episodes of acute
What is the most common scenario in which acute -> chronic
Suppurative type
Presence of ingestible material (e.g. keratin) - constant suppuration
How does suppurative cause acute -> chronic
- If the puss forms an abscess cavity that is deep-seated and drainage is delayed causing abscess to develop thick walls composed of granulation and fibrous tissue
- Rigid walls of abscess cavity therefore fail to come together after drainage
- Cavity becomes organised by ingrowth of granulation tissue
What type of chronic inflammation is caused by foreign bodies
Granulomatous inflammation
What is granulomatous inflammation
Macrophages form multi-nucleate giant cells
Example of recurrent acute inflammation
Cholecystitis where acute causes wall muscle of gallbladder to be replaced by fibrous tissue
Predominant cell type is lymphocyte rather than neutrophil polymorph
What are the five most common appearances of chronic inflammation
- Chronic Ulcer (e.g. of the stomach)
- Chronic abscess cavity
- Thickening of the wall of a hollow viscus by fibrous tissue
- Granulomatous inflammation
- Fibrosis