Pathology - Inflammation Flashcards
What is inflammation?
A local physiological response to tissue injury (not a disease)
What are the benefits of inflammation?
Destroy invading micro organisms = prevent spread of infection
What is the negative of inflammation?
May produce disease
What are 2 causes of chronic inflammation and the cells involved?
Autoimmunity eg. Graves’ disease, MS
Recurrent infection
Macrophages and lymphocytes
What are the 6 causes of acute inflammation?
Examples
Microbial infections (pyogenic bacteria & viruses)
Hypersensitivity (parasites)
Physical agents (trauma, ionizing radiation, heat, cold)
Chemicals (corrosives, acids, alkalis)
Bacterial toxins
Tissue necrosis (death of tissue due to lack of O2 or nutrient filled blood)
5 physical signs of acute inflammation?
What they mean?
Rubor (redness)
Calor (heat)
Tumor (swelling)
Dolor (pain)
Loss of function
Why would you have rubor?
Redness due to dilation of small blood vessels in damaged area (vasodilation)
Why would u have calor?
Heat due to hyperaemia = increased vasodilation = increased warm blood to area
What causes tumor?
Swelling from oedema - accumulation of fluid in ECF
Why would you have dolor?
Pain from stretching/distortion of tissue due to inflammatory oedema
Chemical mediators (bradykinin, prostaglandins and serotonin induce pain)
What are the 3 stages of inflammation in detail?
- Increased vessel calibre - inflammatory cytokines (bradykinin, prostacyclin, NO) mediate vasodilation
- Fluid exudate - vessels become leaky, protein rich fluid forced out of vessel
3.cellular exudate - neutrophil polymorphs into extra vascular space
What is the main cell involved in acute inflammation?
Neutrophils
What is a diagnostic histological feature of acute inflammation?
Neutrophil polymorphs into extra vascular space
What are the 4 stages in neutrophil action of acute inflammation?
Margination (migrate to edge of BV)
Adhesion (selections bind to neutrophil, cause ‘rolling along BV margins)
Emigration + diapedesis (movement out of BV, thru or in between endothelium & other inflammatory cells follow)
Chemotaxis (site of inflammation)
What are the 3 things happening at the site of inflammation?
- Phagocytosis
- Phagolysosome and bacterial killing
- Macrophages clear debris
What are the 5 outcomes of acute inflammation?
Resolution- normal
Supporation - pus formation
Organization - granulation tissue + fibrosis (scar tissue)
Note - cardiac tissue + neurons never resolve, most become this fibrotic tissue
Progression - excessive recurrent inflammation becomes chronic + fibrotic tissue
What is a granuloma?
Aggregates of an epitheloid histocytes (essentially macrophages)
What shape do granulomas form and what disease?
Form a granulomatous ‘horse shoe’ shape
Granulomatous disease
What are some examples or granulomatous diseases?
TB, leprosy, crohns, sarcoidosis (granulomas in organs, especially skin and lungs)
What is the most common cause of granuloma?
TB
What is a feature seen in a granulomatous disease and give an example of which disease?
Central (caseous) necrosis ‘cheese like’
In TB
Is there central necrosis in sarcoidosis, leprosy, vasculitis or crohns?
No central necrosis
The presence of 2 things indicates a parasitic infection?
Granuloma and eosinophil
(Worms)
What do granulomas secrete?
What can this be used as?
ACE
Blood marker
