Acute inflammation Flashcards
What are the causes of acute inflammation?
- Microbial infections
- Hypersensitivity reactions
- Physical agents
- Chemical agents
What are the physical characteristics of acute inflammation?
- Red (dilation of blood vessels)
- Hot (Increase in temperature due to increased blood flow)
- Swollen (due to oedema, and some contribution from inflammatory cells)
- Painful/tender (stimulation of nerve endings by pressure and chemical mediators)
- Loss of function
What is oedema?
Excess of watery fluid collecting in tissues or cavities of the body
What is hyperaemia?
Increased blood flow
What are the phases of acute inflammation and describe them?
Vascular (dilatation and increased permeability) and exudative (fluid and cells escape from permeable venules)
When is there an increased in permeability during inflammation?
During Vascular phase
Define exudate
A mass of cells and fluid that has seeped out of blood vessels during inflammation. They are high protein content, and has a high turnover
Give examples of proteins of an exudate
Immunoglobulin and Fibrin
Highlight the differences between exudate and transudate
Transudate
Is fluid pushed through the capillary due to high pressure within the capillary
No net flow out
Normal vascular permeability
Low protein content
Exudate
Is fluid that leaks around the cells of the capillaries caused by inflammation
Net flow out
Increased vascular permeability
High protein content
What increases vascular permeability?
Chemical mediators including histamine and bradykinin
What are the beneficial effects of acute inflammation
- Dilution of toxins
- Entry of antibodies
- Fibrin formation
- Transport of drugs
- Delivery of nutrients and oxygen
- Stimulation of the immune response
What are the harmful effect of acute inflammation?
Inappropriate inflammatory response
Swelling
Digestion of normal tissue
What is the diagnostic feature of acute inflammation?
Neutrophil accumulation in the extracellular space
What is the function of neutrophil?
Kill organisms Degrade necrotic tissue Produce chemical mediators Produce toxic oxygen radicals Produce tissue damaging enzymes
What is a necrotic tissue
dead tissue that cannot be salvaged and must be removed to allow wound healing to take place