MOD Acute Inflammation

Question 1

Definition

Answer 1

Acute inflammation is innate, stereotyped and immediate response to tissue damage in order to limit the damage.

Question 2

Give an outline of what happens

Answer 2

Vasodilation of arterioles (histamine, c5a, c3a)
Increased vascular permeability (histamine)
Exudation due to pressure changes
Increased lymphatic drainage.
Infiltration of neutrophils
Phagocytosis, killing, activation of immune response
Resolution

Question 3

What causes vasodilation and increased leakage.

Answer 3

Histamine from mast cells, basophils and platelets.

Serotonin from platelets.

Question 4

What do prostaglandins do?

Answer 4

Cause vasodilation
Induce pain and fever
PG3 causes ductus arteriosus to close

Question 5

Describe exudation

Answer 5

Increased capillary hydrostatic pressure and increased vascular permeability allows leakage of plasma into tissue. This raises interstitial colloid oncotic pressure causing yet more exudation.
This results in oedema.

Question 6

What is the function of oedema

Answer 6

Drains into lymphatics with microorganisms and antigens.

Presented to immune system

Question 7

Exudate vs tea sheath

Answer 7

Exudate is a protein rich fluid lost to tissue in inflammation
Transudate is a protein poor fluid lost due to rised capillary hydrostatic pressure only.

Question 8

What are neutrophils

Answer 8

Short life span
Phagocytosis
Release of chemical mediators

Question 9

How to neutrophils enter the tissue

Answer 9

Chemotaxis
Activation
Margination
Rolling
Adhesion
Diapedesis
Emigration

Question 10

Give a chemo attractant. Describe how neutrophils do chemotaxis.

Answer 10

C5a
Binds to receptor on neutrophil PM.
Directional movement down concentration gradient

Question 11

Opsonin

Answer 11

Coat pathogens for phagocytosis

C3b

Question 12

How do neutrophils kill

Answer 12

Oxygen dependent

Oxygen independent - enzymes

Question 13

Function of pain and loss of function

Answer 13

Enforce rest

Question 14

Bradykinin

Answer 14

Vasodilation, venular leakage, pain

Question 15

Complement

Answer 15

Form a membrane attack complex which perforated cell membranes
C3a - vasodilator
C5a - chemoattractant
C3b - Opsonin

Question 16

Local complications

Answer 16

Obstruction of tubes
Damage to normal tissue
Compression of organs
Loss of fluid
Pain and loss of function

Question 17

Systemic consequences

Answer 17

Fever
Leukocytosis
Acute phase response
Changes in plasma protein conc
Shock

Question 18

How does acute inflammation die down

Answer 18

Inflammatory mediators 
Have short half lives
Are degraded
Are diluted by exudate
Produced only in quick bursts if stimulus persists

Question 19

Describe resolution

Answer 19

Return of vascular permeability
Exudate drained
Fibrin degraded
Neutrophils undergo apoptosis

Question 20

sequelae

Answer 20

Abscess
In solid tissue, exudate pulls tissue apart. May be creamy white and filled with neutrophils

Haemorrhagic exudate
Vascular damage

Serous exudate
Few leucocytes but contains plasma proteins

Question 21

Hereditary angiooedema

Answer 21

C1 esterase complement deficience
Non itchy cutaneous angiooedema
Autosomal dominant

Question 22

Alpha 1 antitrypsin deficiency

Answer 22

Protease inhibitor that is released from neutrophils in inflammation.
In lack of, protease act unchecked in lung causing emphysema
Abnormal protein accumulates in liver causing hepatocyte damage

Question 23

Causes

Answer 23

Same as cell injury causes