Lecture 2 - Acute Inflammation

Question 1

define acute inflammation

Answer 1

the response of living tissue to injury initiated to limit the tissue damage

Question 2

what causes acute inflammation?

Answer 2

microbial infections
hypersensitivity reactions
physical agents
chemicals
tissue necrosis

Question 3

what are the macroscopic features of acute inflammation?

Answer 3

calor
rubor
tumour
dolor
loss of function

Question 4

what are the microscopic features of acute inflammation?

Answer 4

vasodilation
gaps form in endothelium
exudation
margination and emigration
macrophages and lymphocytes

Question 5

how is vasodilation brought about in ai?

Answer 5

small adjacent blood vessels dilate with increased blood flow

Question 6

how are endothelium gaps brought about in ai?

Answer 6

endothelial cells swell and retract - no longer completed intact internal lining

Question 7

how is exudation brought about in ai?

Answer 7

vessels become leaky - water, salts, small plasma proteins leak out

Question 8

how is margination and emigration brought about in ai?

Answer 8

circulating neutrophils adhere to swollen endothelial cells (m)
neutrophils migrate through vessel basement membrane (e)

Question 9

how are macrophages and lymphocytes brought about in ai?

Answer 9

migrate in a similar way to neutrophils

Question 10

what are the chemical mediators of vasodilation?

Answer 10

histamine
prostaglandins
c3a
c5a

Question 11

what are the chemical mediators of vascular permeability?

Answer 11

histamine, prostaglandins, kinins

Question 12

what are the chemical mediators of emigration of leukocytes?

Answer 12

leukotrienes
il-8
c5a

Question 13

what do neutrophils do?

Answer 13

phagocytose microorganisms by making contact, recognising and internalising them - phagosomes then fuse with lysosomesmove to the site of injury by chemotaxiscan release toxic metabolites and enzymes when activated

Question 14

what is the acute phase response?

Answer 14

decreased apptite
raised heart rate
altered sleep pattern
changes in plasma concentration of acute plasma proteins

Question 15

give examples of acute phase proteins

Answer 15

c reactive proteins
fibrinogen
alpha1 antitrypsin

Question 16

what causes fever?

Answer 16

endogenous pyrogens, il-1, tnf alpha and prostaglandin are produced

Question 17

what are the possible results of ai?

Answer 17

complete resolution
continued ai with ci (abscess)
ci and fibrous repair, probably with tissue regeneration
death

Question 18

how does resolution come about?

Answer 18

all mediators have short half lives and can be inactivated by degradation, dilution in exudate or inhibition
gradually all changes of ai reverse and vascular changes stop
potential for damaged tissue to regenerate if tissue architecture is intact

Question 19

what are possible complications of ai?

Answer 19

swelling - blockage of tubes
exudate - compression
loss of fluid
pain and loss of function

Question 20

describe a skin blister

Answer 20

caused by heat, sunlight, chemicals
pain and profuse exudate
collection of fluid strips of overlying epithelium
few inflammatory cells giving clear exudate
resolution or scarring

Question 21

describe an abscess

Answer 21

solid tissues
inflammatory exudate forces tissues apart
liquefactive necrosis in centre
may cause high pressure causing pain
may cause tissue damage and squash adjacent structures

Question 22

describe pericarditis

Answer 22

inflammation of serous cavity

pericardium becomes inflamed and increases pressure on heart

Question 23

give examples of disoders of ai

Answer 23

alpha 1 antitrypsin deficiency
inherited complement deficiencies
defects in neutrophil function
defects in neutrophil numbers

Question 24

what is hereditary angio oedema?

Answer 24

caused by deficiency of c1 inhibitor
c1 is a complement protein that cleaves c2 and c4 to form c3
c1 inhibitor inhibits c1 and bradykinin
uninhibited bradykinin increases permeability of endothelia causing oedema
treated with c1 inhibitor infusion or fresh frozen plasma

Question 25

what is alpa 1 antitrypsin deficiency?

Answer 25

alpha 1 antitrypsin inhibits elastase
without the inhibition elastase breaks down lung/liver tissue
causes emphysema and liver sclerosis

Question 26

what is chronic granulomatous disease?

Answer 26

recessive sex linked
immune phagocytes cant form ros
cant kill some bacteria without ros
granulomas formed in an attempt to contain the bacteria