Cell Response To Injury 3 - Inflammation

Question 1

What is acute inflammation?

Answer 1

The initial response taking place in the minutes and hours following injury

Question 2

What is chronic inflammation?

Answer 2

Persistent inflammation taking place alongside attempts at healing

Question 3

What are the functions of acute inflammation?
(9)

Answer 3

• Carriage of proteins, fluid and cells from local blood vessels to the damaged area
• Destruction of the causative agentdriving the inflammation.
• Removal of damaged tissuefrom the site.

• Dilution of toxins
• Entry of antibodies.
• Fibrin formation
• Delivery of nutrients and oxygen
• Stimulation of the immune resonse
• Transport of therapeutic drugs

Question 4

What are the causes of acute inflammation?
(6)

Answer 4

Microbial action
Hypersensitivity
Necrosis
Tissue damage
Corrosive chemicals
Ionising radiation

Question 5

What are the Cardinal signs of inflammation?
(4)

Answer 5

• Heat
• Redness
• Swelling
• Pain
• (Loss of function)

Question 6

How can the cardinal signs of acute inflammation be explained in terms of events occurring at a microscopic level ? (Will be next set of flashcards too - see slides)

Answer 6

Question 7

What are the steps involved in acute inflammation?

Answer 7

Question 8

Acute inflammation - what are some examples of Inflammatory Mediators?

Answer 8

• Cellular mediators of inflammation
• Histamine
• Prostaglandins
• Leukotrienes
• Cytokines/Lymphokines

• Others
• Bacterial products/extraneous factors
• Reactive oxygen intermediates
• Bioactive amines (histamine)

• Plasma derived mediators of inflammation
• Clotting factors
• Complement cascade
• Kallikrein-Kinin system
• Fibrinolytic systen

Question 9

What happens during vascular stages during acute inflammation?

Answer 9

• Inflammatory mediators induce conformational changes in the endothelial cells lining venules increasing permeability
• Cell adhesion molecule (CAM) expression on endothelial surface facilitating margination

• Leukocytes in venules line up along the endothelial wall; margination
• Leucocytes migrate between endothelial cells into the tissues.
• Leucocytes are attracted by chemotaxis to the site of inflammation.
• Fluid flow to the extra-vascular compartment.
• Increased blood flow, and movement of fluid contributes to heat, redness and swelling.

Inflammatory mediators cause conformational changes and CAM expression. Then cell migration along chemotactic gradient to site of inflammation. Then Movement of fluid and protein to extracelluar compartment. Then Continued release of mediators which perpetuates the response until the stimulus is removed (+ve feedback)

Question 10

Which cell adhesion molecules are important in inflammation?

Answer 10

Question 11

What causes Leucocyte Adhesion Deficiency-1?
What causes Leucocyte Adhesion Deficiency-2?

Answer 11

Leucocyte Adhesion Deficiency-1 = a2 integrins

Leucocyte Adhesion Deficiency-2 = E Selectin, P Selectin, L Selectin

Question 12

What does inflammatory exudate contain?

Answer 12

Cells
Protein
Serum

Question 13

What cells are in inflammatory exudate?

Answer 13

• NEUTROPHILS
• later on monocytes (macrophages) and lymphocytes
• occasional erythrocytes

Question 14

Inflammatory exudate - what do neutrophils pass through?
What are the functions of neutrophils modulated by what chemotactic factors ?

Answer 14

i. pass through inter cellular junctions
ii. functions modulated by chemotactic factors including
-C5a
-Leucotriene B4
-Interleukin 8
-Bacterial factors

Question 15

What is the role of neutrophils in inflammatory exudate?
What is respiratory burst?

Answer 15

i. attachment and phagocytosis
ii. production of reactive oxygen intermediates (Respiratory burst)
iii. production of inflammatory mediators

Respiratory burst:
• A rapid release of reactive oxygen species (superoxide radicals and hydrogen peroxide) by neutrophils and monocytes.
• These are released on contact with pathogens and are important in the degradation of internalised bacteria, fungi and other matter.

Question 16

Inflammatory exudate: proteins
What proteins are in inflammatory exudate?

Answer 16

• fluid derived from the circulation
• contains variable amounts of serum proteins
• includes
i. Albumin
ii. Fibrinogen
iii. Immunoglobulins
iv. Complement components

Question 17

What are the systemic effects of acute inflammation?

Answer 17

• Pyrexia
• Constitutional symptoms (e.g. malaise, anorexia and nausea)
• Reactive hyperplasia of Iymph nodes/ spleen
• Haematological changes
• Increased erythrocyte sedimentation rate.
• Leukocytosis.
• Amyloidosis

(Pyrexia is increased body temp/fever, malaise is illness, leukocytosis is increased White blood cell count)

Question 18

What is pus?

Answer 18

‘An inflammatory exudate rich in neutrophils, some of which are dead or dying , through autodigestion in their own enzymes’
• Often contains bacterial debris

Question 19

Acute inflammation summary

Answer 19