Acute & Chronic inflammation Flashcards
What is inflammation?
The host response to tissue damage
Why does inflammation occur?
as a protective response
- to remove/contain cause
- initiate repair
- reinstate useful function
- it is essential for healing
What are the 5 triggers for inflammation?
- foreign body
- infection
- ischaemia/ infarction
- physical/ chemical injury
- immune reaction
In acute inflammation what are the vascular changes to maximise movement of plasma proteins to site of injury?
- Vasodilation
- Increased permeability (leads to OEDEMA)
- blood stasis (pooling the blood at the site of injury
In acute vasodilation the vascular change of vasodilation leads to…
- increased blood flow
- causing redness and heat (erythema)
- endothelial cells of vessel wall contract
- Transcytosis - increased transport of fluid and proteins
In acute inflammation what are the cellular changes to maximise movement of plasma proteins to site of injury?
- margination - RBCs go to centre of lumen and WBCs go peripherally
- rolling - increased amount of leucocytes roll along edge of damaged endothelium
- adhesion - leucocytes stop and adhere to endothelium (cytokines encourage this)
What do the vascular changes in acute inflammation cause?
- cause leakage of intravascular fluid into the extravascular spaces
What is the main aim of inflammation?
to recruit leucocytes to area of damage
What do neutrophils and macrophages do ?
- ingest and kill bacteria and necrotic cells
- promote repair
Where are white blood cells recruited from in inflammation?
vessel lumens
In the cellular changes of inflammation what happens at the transmigration phase?
leucocyte encouraged to pass through endothelium to extravascular space
- chemokines stimulate this
How long does it take for neutrophils to appear and what do they respond to?
6-24 hours
chemokines
How long does it take monocytes to appear ?
24-48hours
opsonin receptors recognise microbes that have been coated with proteins this targets them for what?
phagocytosis
how do leucocytes kill harmful agents?
- attaching to bacteria through opsonin receptors
- leucocytes engulfs the cell
- then kills and degrades, removing its harmful effects
What are the outcomes of the process of acute inflammation?
- healing with connective tissue replacement (fibrosis
- if not resolved chronic inflammation or abscess
What are the causes of chronic inflammation?
- persistent infection or inflammation
eg. parasite, TB, toxic agent (asbestos) or when its an auto-immune disease as cant remove are own cells
Neutrophils not normally present in chronic inflammation as others have been recruited such as ..
macrophages, lymphocytes and plasma cells
In chronic inflammation you can get granulomas, what are these?
- cells try to contain offending agent
- strong activation of macrophages and T lymphocytes
- causes damage to surrounding tissue
What examples of conditions may cause granulomas?
- TB
- rheumatoid arthritis
- chrones disease
What kind of things may cause acute inflammation?
- infarction
- bacterial infection
- trauma
- burn
What kind of things may cause chronic inflammation?
- virus
- autoimmune diease
- acute inflammation that’s not resolved
- persistent infection
What are the clinical signs of acute inflammation?
- redness (from vasodilation)
- heat (from vasodilation
- swelling ( due to vascular permilbilty and fluid moving from intra to extra vascular space)
- Pain
- loss of function
What can chronic inflammation lead to?
fibrosis
