Acute and chronic inflammation Flashcards
(25 cards)
What is inflammation?
A reaction to injury or infection involving cells such as neutrophils and macrophages
When is inflammation good?
- Infection
- Injury
When is inflammation bad?
- Autoimmunity
- When it is an over-reaction to the stimulus
How is inflammation classified?
Acute (neutrophils)
Chronic (macrophages and lymphocytes)
Describe acute inflammation
- Sudden onset
- Short duration
- Usually resolves
Describe chronic inflammation
- Slow onset or sequel to acute
- Long duration
- May never resolve
Which cells are involved in inflammation?
-Neutrophil polymorphs
-Macrophages
-Lymphocytes
-Endothelial cells
-Fibroblasts
Describe features of neutrophil polymorphs
- Short lived cells
- First on the scene of acute inflammation
- Cytoplasmic granules full of enzymes that kill bacteria
- Usually die at the scene of inflammation
- Release chemicals that attract other inflammatory cells such as macrophages
Describe features of macrophages
- Long lived cells (weeks to months)
- Phagocytic properties
- Ingest bacteria and debris
- May carry debris away
- May present antigen to lymphocytes
Describe features of lymphocytes
- Not much cytoplasm, big nucleus
- Long lived cells (years)
- Produce chemicals which attract in other inflammatory cells
- Immunological memory for past infections and antigens
- Plasma cells which make antibodies
Describe features of endothelial cells
- Line capillary blood vessels in areas of inflammation
- Become sticky in areas of inflammation so inflammatory cells (neutrophils) adhere to them
- Become porous to allow inflammatory cells to pass into tissues
- Grow into areas of damage to form new capillary vessels
-Precapillary sphincters open in inflammation
What’s an example of acute inflammation?
Acute appendicitis
Describe features of fibroblasts
- ER for collagen synthesis
- Long lived cells
- Form collagen in areas of chronic inflammation and repair
Describe acute appendicitis
- Unknown precipitating factor
- Neutrophils appear
- Blood vessels dilate
- Inflammation of serosal surface occurs
- Pain felt
- Appendix either surgically removed or inflammation resolves or appendix bursts with generalised peritonitis and possible death
What’s an example of chronic inflammation?
Tuberculosis
Describe tuberculosis
- Caused by mycobacteria which has a waxy cell wall
- No initial acute inflammation
- Mycobacteria ingested by macrophages
- Macrophages often fail to kill the mycobacteria
- Lymphocytes appear
- Macrophages appear
- Fibrosis occurs
What is a granuloma?
Collection of macrophages trying to kill something surrounded by lymphocytes (not effectively)
When are granulomas seen?
In chronic inflammation and in TB
What are different ways to treat inflammation?
-Ice
-Antihistamines
-NSAIDs
-Steroid cream
How does ice treat inflammation?
- Ice causes sphincter muscles on capillaries to shut
- Stops swelling
How does antihistamine tablets/cream treat inflammation?
- Treats mosquito bites
-Histamine is a chemical mediator of acute inflammation
How do NSAIDs treat inflammation?
-Inhibit prostaglandin synthetase
-Prostaglandins chemical mediators of inflammation
What are examples of NSAIDs?
Aspirin and ibuprofen
How does steroid cream treat inflammation?
-Corticosteroids are anti inflammatory
-Bind to DNA up regulate
