Inflammation

Question 0

What are the two stages of inflammation and their purpose?

Answer 0

Vascular events- deliver plasma proteins to the site of injury. Capillaries
Cellular events- deliver wbc to damaged tissues. Venules.

Question 1

What are the four Cardinal signs of inflammation?

Answer 1

Heat, pain, redness, swelling.

Question 2

What occurs during the vascular phase

Answer 2

1. Occurs in the capillaries. Aim is to deliver plasma proteins to damaged or infected tissue.
2. The pre capillary sphincter relaxes increasing blood flow. Causes redness and heat.
3. Permeability of capillaries increases due to active response by endothelium cells as gaps form.
4. Exudate on as blood plasma moves into intracellular, delivering plasma proteins to the site.
5. The lymphatic system usually drains the exudate however during inflammation the capacity of the lymphatic system is exceeded resulting in odema as exudate pools in the tissue.

Question 3

What occurs in the second stage of inflammation?

Answer 3

The vascular phase occurs in the venues. Vessels which drain blood from the capillaries. In this phase wbc are delivered to the infected tissue.

1. Inflamed tissue show excess expression of adhesion molecules on their surface causing wbc to stick to the endothelium. Eg selectin molecules bind neutrophils.
2. Emigration. Wbc moves into the inflamed tissue attracted by cytokines in chemotaxis. Foot like projections called pseudopodia allow cells to push them between cells.

Question 4

What is chemotaxis?

Answer 4

Chemotaxis is the movement of cells across a concentration gradient resulting from cells being attracted or repelled by a chemical.

Question 5

What is acute inflammation and how is characterised?

Answer 5

Short duration immediate response. Rich in neutrophils. Aims to limit tissue damage and isolate toxins. Occurs before immune system kicks in.

Question 6

What is chronic or systemic inflammation?

Answer 6

Caused by an increased release of pro inflammatory cytokines from immune regulated cells and activation of innate immune system.
Characterised by seeing multiple immune cells such as macrophages as well as neutrophils.

Question 7

What are the effects of systemic inflammation?

Answer 7

Pyre is (fever caused by circulating cytokines)
Malaise
Weight loss
Acute phase protein production such as fibrinogen and coagulation factors. Mediated by il1&6

Question 8

What is pus?

Answer 8

Pus occurs during supprative inflammation due to pyrogenic bacteria. Formed by neutrophils, dead bacteria and exudate.
Accumulation of pus in an enclosed space is an abscess.