Acute Inflammation

Question 1

Acute Inflammation

Answer 1

Immediate and early response to injury, designed to deliver leukocytes to site of injury

Question 2

Diverticulitis

Answer 2

Inflammation of

Question 3

Diverticulosis

Answer 3

A disease or condition

Question 4

Causes of Inflammation

Answer 4

1. Microbial Infection
2. Hypersensitivity reactions
3. Physical agents (trauma, radiation, heat injury)
4. chemicals (corrosives, acids, bacterial toxins)
5. Tumour necrosis (Secondary to ischaemia)

Question 5

What are hypersensitivity reactions?

Answer 5

Excessive immune response -> Tissue damage

Question 6

Microbial Infection includes…

Answer 6

1. Bacterial endotoxins
2. Bacterial exotoxins
3. Viral intracellular multiplication
4. organisms causing hypersensitivity reactions

Question 7

Bacterial exotoxins

Answer 7

chemicals released by bacteria which stimulate inflammation

Question 8

Bacterial endotoxins

Answer 8

Associated with bacterial cell walls, also stimulate inflammation

Question 9

Viral intracellular multiplication

Answer 9

leading to cell death, debris then stimulates inflammation

Question 10

Cardinal signs of acute inflammation and why

Answer 10

1. Redness (rubor)- due to dilation of vessels
2. Heat (calor)- due to increased blood flow
3. Swelling (tumor)- due to accumulation of fluid & increase in inflammatory cells migrating to the area
4. Pain (dolor)- due to physical distortion of tissue & release of chemical mediators (Bk, PGs)
5. Loss of function (functio laesa)

Question 11

Stages of Inflammation

Answer 11

1. Release of chemical mediators
2. Vasodilation
3. Increased vascular permeability
4. Fluid accumulation
5. Cellular recruitment
6. Phagocytosis

Question 12

Components of Acute Inflammation

Answer 12

1. Vascular changes
   -change in vessel calibre
   -Increase in vascular permeability
2. Cellular events
   -formation of cellular exudate

Question 13

Vascular Changes in Acute Inflammation

Answer 13

1. Changes in vascular calibre
2. Initial transient constriction
3. Then vasodilation (can last 15m to several hours)

Question 14

Exudation

Question 15

Formation of cellular exudate

Answer 15

Accumulation of neutrophil polymorphs

Question 16

Neutrophils characteristics

Answer 16

1. can move
2. can stick to opsonised microorganisms
3. Phagocytosis
4. can kill microorganisms

Question 17

How do neutrophils move?

Answer 17

-by contracting cytoplasmic microtubules
-Calcium ion dependent mechanism, chemotaxis in response to inflammatory chemicals

Question 18

How do neutrophils bind to opsonised microorganisms?

Answer 18

Once bacteria have encountered immunoglobulins or complement components, neutrophils can bind to them

Question 19

How do neutrophils kill?

Answer 19

A variety of intracellular methods to produce microbicidal agents
Eg, producing hydrogen peroxidase, to react with cytoplasmic myeloperoxidase

Question 20

Margination

Answer 20

Loss of intravascular fluid
Slowing of flow to the site

Allows neutrophils to marginate

Question 21

Adhesion

Answer 21

Also known as “pavementing”
Neutrophils adhere to vascular endothelium

Caused by interaction between paired adhesion molecules on the neutrophil and endothelial surfaces

Question 22

Emigration

Answer 22

Pass between endothelial cells
Through basal lamina and into adventitia

Question 23

Components of Acute Inflammation

Answer 23

-Cells: Endothelial and Inflammatory
-Chemical agents: cytokines, complement, histamine, PGs

Question 24

chemical mediators- early chemical events

Answer 24

1. Histamine and thrombin are released by original inflammatory stimulus
   -These chemicals cause upregulation of P-selectin and platelet activating factor (PAF) on the endothelial cells
2. Neutrophils start to roll along endothelial wall
   -Ligands on the neutrophil surface engage with the P-selectin on the endothelial cells

PAF docks with corresponding receptor on neutrophil and promotes expression of other molecules (LFA-1, MAC-1) – overall end result is firm neutrophil adhesion to endothelial surface

Question 25

Chemical mediators released by cells

Answer 25

1. Histamine 2. Lysosomal compounds 3. Leukotrienes 4. Prostaglandins 5. Serotonin 6. Chemokines

Question 26

Histamine...

Answer 26

1. Causes vascular dilation and permeability 2. Released mainly by mast cells

Question 27

Lysosomal compounds

Answer 27

1. Lots of different functions, such as vascular permeability 2. Some can stimulate histamine release from mast cells 3. Released by neutrophils

Question 28

Leukotrienes

Answer 28

1. Vasoactive properties 2. Often made in neutrophils from arachidonic acid

Question 29

Prostaglandins

Answer 29

1. Also derived from arachidonic acid 2. Some cause increased vacular permeability 3. Some cause platelet aggregation 4. Released by lots of cell types

Question 30

Serotonin

Answer 30

1. Vasoconstrictor 2. Released by platelets

Question 31

Chemokines

Answer 31

1. Family of chemicals which attract more white blood cells to site of inflammation 2. Eg IL-8 attracts neutrophils

Question 32

Plasma factors- cascade system in plasma

Answer 32

1. Coagulation system 2. Kinins 3. Fibrinolytic system 4. Complement system

Question 33

Coagulation system

Answer 33

converts soluble fibrinogen into fibrin

Question 34

Kinins

Answer 34

Activated by coagulation factor XII Bradykinin important peptide in mediating vasodilation, pain