acute and chronic inflammation Flashcards
What is inflammation?
the local physiological response to tissue injury
A reaction to injury or infection involving
cells such as neutrophils and macrophages
When is inflammation good?
during infection and injuries
- to destruct invading microorganisms
- the walling off of an abscess cavity, preventing the spread of infection
When is inflammation bad?
autoimmunity
when it is an over-reaction to the stimulus
( when It shouldn’t be there)
An abscess in the brain would act as a space-occupying lesion compressing vital surrounding structures
Fibrosis resulting from chronic inflammation may distort the tissues and permanently alter their function
How is inflammation classified?
acute
chronic
Describe Acute inflammation
The initial and often transient series of tissue reactions to injury
Sudden onset
Short duration
Usually resolves
NEUTRAPHILS
Describe Chronic inflammation
Slow onset or sequel to acute Long duration
May never resolve
MACROPHAGES AND LYMPHOCYTE
What cells are involved in inflammation?
Neutrophil polymorphs Macrophages
Lymphocytes
Endothelial cells
Fibroblasts
Describe Neutrophil polymorphs
short lived cells
first on the scene of acute inflammation
don’t live very long- a few days
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 Macrophages
come after neutrophils
bags of enzymes- phagocytic properties
can live for a long time- weeks- months
ingest bacteria and debris
may carry debris away
may present antigen to lymphocytes.
aids in long immunity
Describe Lymphocytes
long lived cells- years- whole life time
produces chemicals which attract in other inflammatory cells
immunological memory for past infections and antigens
not much cytoplasm
big nucleus
Describe Lymphocyte- plasma cell
antibody making factory
more ER as making proteins- antibodies
around infection some lymphocytes turn into plasma cells for this purpose
Describe 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 yo form new capillary vessels.
Descrive Fibroblasts
long lived cells
form collagen in areas of chronic inflammation and repair
come in quite late to inflammation
Give examples of acute inflammation
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
Give examples of chronic inflammation
-Tuberculosis
– No initial acute inflammation
– Mycobacteria ingested by macrophages
– Macrophages often fail to kill the mycobacteria – Lymphocytes appear
– Macrophages appear
– Fibrosis occurs
