Acute Inflammation Flashcards
(38 cards)
Inflammation
response of living tissue to injury
Two phases of inflammation
Vascular phase
Cellular phase
Describe the the vascular phase
Changes in blood flow
Accumulation of exudate
Cellular phase
- Removal of pathogens, necrotic tissue
(e.g. delivery of neutrophils) - Release inflammatory mediators
What causes inflammation
Trauma
Hypersensitivity
Micro-organisms
Necrosis
What happens in the vascular phase
- Vasoconstriction (sec)
- Vasodilation (min)
- Increased permeability
Hydrostatic pressure
Pressure exerted on a vessel wall by fluid
(Pushed fluid away)
Oncotic pressure
Pressure exerted by proteins
(Draws fluid towards)
Signs of acute inflammation
Rubor, tumour, calor, dolor, loss of function
Explain the tissue changes that occur in acute inflammation
- ⬆️ capillary hydrostatic pressure
- Plasma proteins move into interstitium,
⬆️ Interstitial oncotic pressure - Fluid moves OUT of vessel INTO interstitium
➡️OEDEMA - Movement of fluid OUT of vessel
- Reduced flow through vessel
➡️ STASIS
Types of interstitial fluid
Exudate
Transudate
Difference between exudate and transudate
Exudate is protein rich, ⬆️vascular permeability, occurs in inflammation
Transudate is due to ⬆️capillary hydrostatic pressure/⬇️capillary oncotic pressure, vascular permeability unchanged, occurs in heart, hepatic, renal failure
How is the vascular phase in acute inflammation effective
-Interstitial fluid dilutes toxins
-Exudate delivers proteins such as immunoglobulins
-Carry antigens to lymph nodes
Features of neutrophil
-Primary WBC involved in acute inflammation
-Trilobed nucleus
List the key chemical mediators involved in acute inflammation
How do neutrophils escape vessels
Margination
Rolling
Adhesion
Emigration (Diapedesis)
Typical features of inflammation
Immediate
Short duration
Innate
Stereotyped
Limits damage
What is the ‘Starling’s Law’
Movement of fluid is controlled by the balance of hydrostatic pressure and oncotic pressure
How is the vascular phase effective
-Interstitial fluid dilutes toxins
-Exudate deliver proteins
(e.g. Fibrin- mesh limits spread of toxin,
Immunoglobulins- from adaptive immune response)
Carry antigens to lymph nodes)
What are the adhesion molecules involved in the cellular phase of acute inflammation
Selectins
Integrins
Which processes are the adhesion molecules responsible for
Selectins- rolling
Integrins- adhesion
How is selectin involved in the cellular phase of acute inflammation
-Expressed on activated endothelial cells
-Cells activated by chemical mediators
How is integrin involved in the cellular phase of acute inflammation
-Found on neutrophil surface
-Change from low to high affinity state
How do neutrophils move through the interstitium
Chemotaxis:
Movement along an increasing chemical gradient of chemoattractants
