acute and chronic inflammation Flashcards
What is inflammation?
A reaction to an injury or infection involving cells such as neutrophils and macrophages.
What are the characteristics of acute inflammation?
Sudden onset
Short duration
Usually resolves
Involves neutrophils
What are the characteristics of chronic inflammation?
Slow onset or sequel to acute inflammation
Long duration
May never resolve
Involves lymphocytes and macrophages
Define acute inflammation
The initial and often transient series of tissue reactions to injury
Define chronic inflammation
The subsequent and often prolonged tissue reactions following the initial response
What is good inflammation?
In reaction to infection or injury
What is bad inflammation?
Autoimmunity or over-reaction to the stimulus
Neutrophil polymorphs
Short lived cells
First on the scene of acute inflammation
Cytoplasmic granules full of enzymes that kill bacteria (ingest bacteria)
Usually die at the scene of inflammation
Release chemicals that attract other inflammatory cells such as macrophages
Macrophages
Long lived cells (weeks to months) Phagocytic properties Ingest bacteria and debris May carry debris away May present antigen to lymphocyte
Lymphocyte
Long lived cells (years - potentially life long)
Produce chemicals which attract in other inflammatory cells
Immunological memory for past infections and antigens
Endothelial cells
Line capillary blood vessels in areas of inflammation
Become sticky in areas of inflammation so inflammatory cells adhere to them
Become porous to allow inflammatory cells to pass into tissues
Grow into areas of damage to form new capillary vessels
Why are areas of inflammation red and swollen?
Red = most capillary aren’t usually open, open when inflamed so that more rbc go through capillary so more inflammatory cells can get to tissues.
Swollen - proteins go out of capillary, water follows
Fibroblasts
Long lived cells
Form collagen in areas of chronic inflammation and repair
