Vascular And Cellular Events In Acute Inflammation Flashcards
What do vascular changes in during inflammation aim to maximise
The movement of plasma proteins and circulating cells out of the circulation and into the site of infection/injury
What do vascular changes consist of?
Changes in blood flow (vasodilation of arterioles and opening of new capillary beds) and permeability of vessels
How is vasodilation achieved?
The action of NO and Histamine on vascular smooth muscle
How is stasis in the vessels reached?
The loss of fluid and increase in vessel diameter causes blood to flow slower and the concentration of rbcs until stasis is reached
What effect do the mediators released by nfection/tissue damage have on the vascular endothelial cells?
The endothelial cells express increased numbers of adhesion molecules as a result
Why do endothelial cells express more adhesion molecules
To allow leukocytes to adhere to the endothelium and migrate into the interstitial tissue.
Which changes cause increased vascular permeability?
Who elicits them?
Contraction of endothelial cells resulting in increased interendothelial spaces
- Elicited by bradykinin, histamine, leukotriens and substance P
Or increased permeability can be due to endothelial injury and necrosis, or increased transport across endothelial cells
Which are the most important leukocytes during inflammation?
Phagocytes such as neutrophils and monocyte-macrophages
How are leukocytes recruited to the site of injury?
- marginalisation in the lumen of the vessel
- rolling until the site of inflammation
- adhesion to the endothelium
- diapedesis (transmigration across the endothelium towards the chemotactic gradient)
