Acute Inflammation

Question 1

Define inflammation

Answer 1

Inflammation is a protective, non-specific response of a living vascularized tissue to cellular injury

Aim:
Remove cause of injury
Clean up dead or dying cells and tissues

Question 2

Differentiate between acute and chronic inflammation

Answer 2

Acute inflammation:
I. Hours to days
II. Exudation of fluid and plasma proteins
III. Infiltration by neutrophils(polymorphonuclear)

Chronic inflammation:
I. Days to years
II. Infiltration of monocyte-macrophage system(mononuclear)

Question 3

What are the five signs of inflammation

Answer 3

Calor-heat 
Dolor-pain 
Rubor-redness
Tumor-swelling 
Loss of function

Question 4

Describe the vascular events of inflammation

Answer 4

Recruitment of neutrophils
⬇️
Increased blood flow
⬇️
Arteriolar vasodilation(arteriolar end)

Redness
⬇️
Engorgement of capillary bed

Transudation
⬇️
Increased vascular permeability(venular end)

Swelling 
⬇️
Exudation(plasma 
proteins and leukocytes)
⬇️
Edema
⬇️
Stasis(⬆️viscosity and ⬇️flow)

Question 5

Describe the cellular events of inflammation

Answer 5

Neutrophil recruitment 
⬇️
Margination
⬇️
Rolling
⬇️
Adhesion 
⬇️
Transmigration
⬇️
Chemotaxis 
⬇️
Phagocytosis

Question 6

Marginated leukocytes roll on the endothelial surface by forming transient adhesions via the selection family of proteins which are:

Answer 6

• E-selectin on endothelial cells
• P-selectin on endothelial cells and platelets
• L-selectin on leukocytes

Question 7

What mediates adhesion?

Answer 7

Endothelial cells:
ICAM-1 and VCAM-1 (members of Ig superfamily)

Leukocyte:
VLA-4 and LFA-1 (integrins)

Question 8

Where does transmigration occur and what mediates it?

Answer 8

In the venules

PECAM-1 of the Ig superfamily