L4- Acute Inflammation

Question 1

Acute inflammation

Answer 1

Non-specific initial reaction to tissue damage

Question 2

Acute inflammation - causes

Answer 2

Tissue death

• Ischaemia
• Trauma
• Toxins
• Chemical insults
• Thermal injury
• Radiation

Infection
-Especially bacterial (‘pyogenic’)

Question 3

Purpose of acute inflammation

Answer 3

Clear away dead tissues

Locally protect from infection

Allow access of immune system components

Question 4

Cardinal signs’ of inflammation

Answer 4

Calor= heat
Dolor= pain
Rubor= redness
Tumor= swelling

Question 5

Components of the acute inflammatory response …reactions

Answer 5

Vascular reaction - dilatation (=rubor), changes in flow

Exudative reaction - formation of inflammatory exudate (=tumor)

Cellular reaction - migration of inflammatory cells out of vessels

Question 6

Vascular reaction

Answer 6

Microvascular dilatation
Initially flow is increased and then decreased
There is an increased permeability (mediated and non mediated)

Mediated: Histamine, Bradykinin, NO, complement components

Non mediated: Direct damage to endothelium e.g toxins, physical agents

Question 7

Exudative reaction

Answer 7

formation of inflammatory exudate (=tumor)
Protein rich:
-Immunoglobulins
-Fibrinogen

e.g The heart in a case of pericarditis

Question 8

Cellular reaction

Answer 8

Migration of inflammatory cells out of vessels

Accumulation of neutrophils in extracellular space

In severe cases, accumulation of neutrophils, cellular debris and bacteria forms pus
-e.g acute meningitis caused by a pyogenic (=pus forming) bacterial infection

-bronchopneumonia - the airspaces are filled with a neutrophil rich exudate

Question 9

Neutrophils

Answer 9

Produced in bone marrow
Commonest white cell in blood
Increase in acute inflammation
Motile, amoeboid, can move into tissues
Directional chemotaxis 
Short lifespan (hours in tissues)

Phagocytic, microbiocidal

Question 10

Steps in a cellular reaction (Migration)

Answer 10

he movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue. Also called migration

Margination –> Rolling- adhesion (pavementing) –> diapedesis

Question 11

Cell derived Mediators of acute inflammation

Answer 11

Prostaglandins
Leukotrienes
PAF
Cytokines (IL1,8; TNFa)
NO
Chemokines
 Histamine

Question 12

Plasma derived Mediators of acute inflammation

Answer 12

Kinin system
Clotting pathway
Thrombolytic pathway
Complement pathway

Question 13

Outcomes of acute inflammation

Answer 13

Minimal tissue damage = resolution

Some tissue damage =Fibrosis

Marked neutrophil reaction with tissue damage = Suppuration- abscess

Damaging agent persists = Chronic inflammation