Reaction of living vascularised tissue to sub-lethal cellular injury. Evolutionary development to protect against infection and trauma.
Name the function of inflammation?
Remove cause of injury and initiate repair
Name the causes of inflammation?
Infection tissue destruction- mechanical trauma, chemical injury, radiation
Why are vascular changes in inflammation important?
Dilation and increased blood flow to injured area enables rapid delivery of inflmatory cells and mediators.
Name the local cardinal signs for Acute inflammation.
RUBOR – redness CALOR – heat TUMOR – swelling DOLOR – pain LOSS OF FUNCTION
What causes loss of function in acute inflammation?
Loss of function is due to swelling and pain
What are exudates?
What comes out of leaky capillaries fluid, cells, proteins including fibrin, antibodies etc. think of exudes
What is the function of exudate?
Fluid dilutes pathogen and allows soluble mediators to spread easier within the area
Fibrin from the exudate walls off pathogen to stop it spreading and gives inflammatory cells a substrate to hold onto
What does histamine lead to?
Vasodilation Increased vascular permeability
What is formed in an acute inflammation?
Exudate is formed
What is the main cell invoved in acute inflammation?
In acute inflammation, what needs to occur for tissue to return back to normal?
Tissue cells need to contain cells that can regenerate to replace lost cells Little structural damage done- cells need a framewrok to build on
What happens if tissue loss is too great and cells unable to regenerate?
Replace normal tissue with fibirous scar tissue
What hinders repair?
–POOR NUTRITION - Require protein for collagen production, and energy for cell function.
Vitamin C – needed by fibroblasts to make collagen
Vitamin A - required for epithelial regeneration
–MINERAL DEFICIENCY eg. Zinc
–SUPPRESSED INFLAMMATION by steroids, old age, diabetes
–POOR BLOOD SUPPLY eg. ischaemic leg ulcers
–PERSISTENT FOREIGN BODY eg. splinter
–MOVEMENT e.g across a fracture site -> need for a cast.
Name the possible complications of repair?
–Excess collagen deposition (pic on right)
–Fibrous scar tissue contracts as it matures. If scarring occurs across a joint can cause poor joint mobility.
•Impaired organ function
–e.g fibrous scars in the myocardium after a heart attack.
Name the histological features of acute inflammation?
Nuetrophils predominate eosinophils and mast cells are there
What is chronic inflammation?
Inflammation of prolonged duration in which active inflammation, tissue destruction and attempts at repair occur simultaneously
What are the causes of chronic inflammation?
Persistent damage Persistent infection (HCV, TB) Prolonged exposure to toxic agent (uric acid) Autoimmunity (RA, SLE) Foreign body (splinter, silica)
Name the cells of chronic inflammation?
Macrophages Lymphocytes and plasma cells
Name what can be formed in chronic inflammation?
Histological features of Chronic inflmmation?
presence of granulation tissue, Macrophages Lymphocytes and nuetrophil exudate
What is granulomatous inflammation?
Particular form of chronic inflammation showing granuloma formation.
Granulomas are formed in an attempt to wall off pathogens too
What is a granuloma?
Cluster of macrophages Involves specific immune reaction T cells
What are the causes of granulomatous inflammation?
Infection – TB, fungi Foreign material Reaction to tumours Immune diseases (sarcoid, Crohn’s)
How does the liver respond to chronic inflammation anywhere in the body?
The liver produces and releases increased amounts of serum amyloid A protein into the blood
this protein has roles in eg recruiting immune cells for inflammation etc. HOWEVER can lead to implications eg amyloidosis
What are the harmful effect of inflammation?
-damage to local tissues/scarring
-can affect nearby tissues
•Can evolve into systemic inflammatory reaction and secondary multi-organ failure
–E.g. Septic shock
Amyloidosis is when an abnormal protein called amyloid builds up in your tissues and organs. When it does, it affects their shape and how they work. Amyloidosis is a serious health problem that can lead to life-threatening organ failure.
What type of inflammation follows acute inflammation but can occasionally develop straight off?
What are the main cell types for chronic inflammation?
Lymphocytes and Macrophages
State the differences between acute and chronic inflammation?
Name the differences between chronic and acute inflammation?