Pathology Flashcards
(158 cards)
When is inflammation a good reaction ?
Infection
Injury
When is inflammation bad ?
Autoimmunity
Over-reaction to stimulus
How is acute inflammation classified?
Sudden Onset
Short duration
Usually resolves
How is chronic inflammation classified?
Slow onset or sequel to acute
Long duration
May never resolve
What cells are involved in inflammation?
Neutrophil polymorphs - acute inflammation Macrophages Lymphocytes Endothelial cells Fibroblasts
What are 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
What are Macrophages?
- Long lived cells (weeks to months)
- Phagocytic properties
- Ingest bacteria and debris
- May carry debris away
- May present antigen to lymphocytes
What are lymphocytes?
• Long lived cells (years)
• Produce chemicals which attract in other
inflammatory cells
• Immunological memory for past infections
and antigens
What is the importance of endothelial cells in inflammation?
• 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
What are fibroblasts?
- Long lived cells
* Form collagen in areas of chronic inflammation and repair
What is an example of acute inflammation?
• Acute appendicitis
What happens during 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 an example of Chronic inflammation?
Tuberculosis
What happens during TB inflammation
– No initial acute inflammation – Mycobacteria ingested by macrophages – Macrophages often fail to kill the mycobacteria – Lymphocytes appear – Macrophages appear – Fibrosis occurs
What is the definition of acute inflammation?
The initial and often
transient series of tissue reactions to injury
What is the definition of chronic inflammation?
The subsequent and
often prolonged tissue reactions following the
initial response.
What type of cells are commonly seen histologically in TB?
Multinucleate giant cell - macrophages fused together
seen also in reaction to silica in the lungs.
What is commonly seen on a X-ray of a patient that has overcome TB?
Apical fibrosis
What is resolution?
–initiating factor removed
–tissue undamaged or able to regenerate
What is repair?
–initiating factor still present
–tissue damaged and unable to regenerate
How does repair work?
• replacement of damaged tissue by fibrous tissue • collagen produced by fibroblasts • examples –heart after myocardial infarction –brain after cerebral infarction –spinal cord after trauma
Which cells regenerate?
- hepatocytes
- pneumocytes
- all blood cells
- gut epithelium
- skin epithelium
- osteocytes
which cells do not regenerate?
- myocardial cells
* neurones
What is chirrosis?
Liver fibrosis and regenerative nodules causes by repetitive injury ie: alcoholism