2. Inflammation And Repair - BP

Question 1

Why is incr. vascular permeability necessary in inflammation?

Answer 1

These changes allow edema of the interstitial tissue to be formed.

Question 2

What are the 5 mechanisms for increasing vascular permeability?

Answer 2

1. Endothelial contraction
2. Endothelial cell retraction
3. Direct endothelial injury
4. Delayed prolonged response
5. Leukocyte mediated damage

Question 3

What are the mediators, the time course, and the mechanism of endothelial cell retraction?

Answer 3

Mediators –> TNF + IL-1.
How –> Structural rearrangement of cytoskeleton.
Time course –> 4-6hrs (delayed response, long lived).

Question 4

What is the mechanism of action of endogenous chemotactic agents?

Answer 4

Most via activation of GTPases, which cause polymerization of actin.

Question 5

How do the WBCs recognize foreign material?

Answer 5

Via the mannose and scavenger receptors.

Question 6

Where do we see serous inflammation?

Answer 6

Viral infections and burns.

Question 7

Where do we see fibrinous inflammation?

Answer 7

Uremic and post myocardial infarct pericarditis.

Question 8

Where do we see purulent inflammation?

Answer 8

In bacterial and fungal infections.

Question 9

What are the 6 outcomes of acute inflammation?

Answer 9

1. Resolution
2. Abscess formation
3. Ulcers
4. Fistula formation
5. Chronic inflammation
6. Scar formation

Question 10

What are the requirements for abscess formation?

Answer 10

The body cannot get rid itself of the inciting agent, or the process of repair and scarring is occurring more rapidly in the tissue around the site of abscess.

Question 11

Mention 4 complications of abscess.

Answer 11

1. Pain
2. Fever
3. Rupture
4. Swelling

Question 12

What is the definition of the ulcer?

Answer 12

Loss of mucosa and deeper tissues.

If ONLY the mucosa is lost, the correct term is erosion.

Question 13

What are the requirements for ulcer formation?

Answer 13

The body cannot rid itself of the inciting agent.

Question 14

What is the microscopic morphology of an ulcer?

Answer 14

4 layers, which recapitulate steps from acute inflammation to repair

1. Fibrin
2. Neutrophils
3. Granulation
4. Fibrosis

Question 15

Mention some complications of an ulcer?

Answer 15

1. Pain
2. Hemorrhage (if it involves a vessel)
3. Perforation –> hemorrhage within a cavity/lumen of the GI tract.

Question 16

What is a fistula?

Answer 16

Anomalous patent conception between 2 organs –> most common in organs with lumen.

Question 17

Mention some requirements for fistula formation.

Answer 17

1. Inflammation involving the FULL thickness of the wall of an organ, duct, or blood vessel.
2. The wall adheres to an adjacent wall, which is subsequently involved by the inflammatory process –> allow communication between the lumens.

Question 18

Mention 5 important mediators in repair and their actions.

Answer 18

1. EGF –> stimulates granulation tissue formation.
2. VEGF –> induces blood vessel formation.
3. PDGF –> promotes migration and proliferation of fibroblasts, smooth muscle cells! and monocytes.
4. FGF –> blood vessel formation and wound repair via macros, fibros, endothelial cell migration.
5. TGF-β –> growth inhibitor for epithelium.

Question 19

What is the time frame of scarring?

Answer 19

24hrs –> begin.
3-5 days –> granulation tissue is formed.
Week 2 –> collagen deposition + edema and infl. absent.
1 month –> scar consists of collagen - strengthens over time.

Question 20

Why is vasodilation necessary in inflammation?

Answer 20

1. Incr. Hydrostatic pressure by slugging of blood flow.

2. Also causes margination of leukocytes along the wall of the vessel.