Lecture 9

Question 1

Define the term acute inflammation:

Answer 1

a rapid and local response to limit tissue damage due to an injury

Question 2

Explain the key processes that are occuring in the vascular process:

Answer 2

1. Transient vasoconstriction
   - Neurogenic – occurs within seconds
   - Slows blood (stasis) to the site of the injury
2. Arteriolar dilation
   - Capillary beds open
   - Histamine, nitric oxide release
   - Increased blood to the site of injury
3. Increased blood viscosity
   - Blood stasis
   - Impedes outflow
4. Increased vascular permeability
   - Hydrostatic and osmotic forces
   - Fluid and plasma proteins enter interstitial space
5. Leukocyte extravasation
   - Cells move from blood to site of injury

Question 3

What are the key steps that are involved in leukocyte extravasation?

Answer 3

1. Marginations- slowing of blood and binding of activated endothelial cells to cell wall (via selectins)
2. Transmigration- leukocytes move across the surface endothelium & basement membrane (by help of integrins)
3. Tissue migration –chemo-attractants guide leukocytes through to site of tissue injury