Acute Inflammation Flashcards
What are the clinical features of acute inflammation ?
RUBOR TUMOR CALOR DOLOR LOSS OF FUNCTION
What happens to the blood vessels in acute inflammation ?
1) transient vasoconstriction of arterioles - few seconds
2) vasodilation of arterioles
3) vasodilation of blood vessels
4) increased permeability
5) STASIS due to increased RBCs + increased viscosity of blood
What cells is histamine released from?
Mast cell, basophils, platelets
Which chemical mediator acts immediately in an acute inflammation response and how quickly ?
Histamine
Within 30 mins
What does release of histamine do?
- vasodilation
- increased permeability
- Pain
What is bradykinin and what does it do?
Inflammatory chemical mediator
Peptide
Causes vasodilation = reduced bp
What response do leukotrienes evoke and which condition are leukotrienes particularly troublesome?
Bronchiole constriction
Asthma
What are the two types of oedema?
Transudate
Exudate
What is the difference between transudate oedema and exudate oedema ?
Exudate oedema = high protein content
Transudate oedema = low protein content
Which type of oedema do you get in acute inflammation ?
Exudate
What type of oedema would you expect in cardiac failure/ venous outflow obstruction
Transudate - oedema due to hydrostatic pressure imbalance
What is polymorphonuclear leucocyte?
Neutrophil
What is the primary type of white blood cell involved in acute inflammation?
Neutrophil
How do neutrophils infiltrate into the tissue ?
Margination - line the endothelium
Rolling - roll along endothelium
Adhesion - stick to endothelium via receptors
Emigration - neutrophils enter blood vessel walls- (cause cells junctions to relax, digest the basement membrane & move in)
Which important protein is found in exudate oedema ?
What is its role in acute inflammation ?
Fibrin
Keeps inflammation local and stops it spreading
How do histamines and leukotrienes increase vascular permeability?
Cause endothelial contraction - resulting in gaps for protein containing fluid to leak out.
How do cytokines IL-1 & TNF increase vascular permeability?
Cytoskeleton reorganisation
What is transcytosis?
What causes this?
Fluid moving across wall of non leaky blood vessel
VEGF
What is the commonest type of inflammatory cell?
Neutrophil
How many lobes does a neutrophil have?
Multiple
What are the 4 stages of neutrophil infiltration ?
Migration
Rolling
Adhesion - loose then tight
Emigration
What causes migration of the neutrophils?
Stasis of the blood
How do the neutrophils emigrate into the tissue?
- relaxation of the endothelial cell junctions
- digestion of the vascular basement membrane
What is diapedesis?
Seen in inflammation - Passage of blood cells through intact capillary walls
What are 3 chemotaxins ?
C5a
LTB4
Bacterial peptides
How do neutrophils move to site of injury ?
Chemotaxis
What are the steps in chemotaxis ?
- receptor on neutrophils binds to ligand (chemotaxins)
- causes rearrangement of cytoskeleton
- production of a pseudopod
- attracts more neutrophils
Once in the tissue what do neutrophils do?
Phagocytose
Name 2 opsonins
Fc (fixed component on all antibodies)
C3b
List 3 o2 independant killing mechanisms?
- lysozyme enzymes : eg hydrolases
- defensins (cationic proteins)
- BPI (bacterial permeability increasing protein
What are 3 families of chemical mediators ?
Proteases
Prostaglandins/leukotrienes
Cytokines/chemokines
The proteases involved in acute inflammation are found where?
They are produced where?
Plasma
Liver
Where are plasma proteins produced?
Liver
What are 3 proteases involved in acute inflammation ?
Kinins
Complement
Clotting factors
What are the metabolites of arachidonic acid?
Prostaglandins
Leukotrienes
Name 2 cytokines ?
Interleukin 1
TNF alpha
What are chemokines ?
Smaller cytokines (proteins)
Which chemical mediators result in increased blood flow?
- histamine
- prostaglandins
Which chemical mediators result in increased vascular permeability ?
Histamine
Leukotrienes
Which chemical mediators result in neutrophil chemotaxis ?
C5a, BPI (BACTERIAL PEPTIDES), LTB4
Which chemical mediators are responsible for phagocytosis ?
C3b
What is the hallmark of acute inflammation?
- exudate of oedema fluid
- infiltration of inflammatory cells
What is cardiac tamponade?
Compression of heart due to too much fluid in the pericardium
What are local complications of acute inflammation?
- swelling
- exudate
- loss of fluid
- pain
- loss of function
What are systemic effects of acute inflammation ?
Fever Leukocytosis Acute phase response Acute phase proteins Shock
What are 5 acute phase proteins
CRP Alpha 1 antitrypsin Haptoglobin Fibrinogen Serum amyloid A protein
Give some examples of the acute phase response ?
Loss of appetite
Raised pulse rate
Altered sleep pattern
Give 2 examples of endogenous pyrogens?
IL-1
TNF alpha
WHAT IS SHOCK?
circulatory failure
What 4 things can happen after development of acute inflammation ?
- resolution
- abscess
- chronic inflammation + fibrous repair
- Death
Name 2 inhibitors of acute inflammatory changes
Lipoxins
Endothelin
Acute inflammation of meninges can lead too..
Swelling and compression of brain
Thrombosis and reduced cerebral perfusion
Which organism causes lobar pneumonia ?
Streptococcus pneumoniae
What are 5 clinical features of a patient with lobar pneumonia?
- fever
- prostration
- Hypoxaemia
- Breathlessness
- dry cough
When examining the exudate of a patient with a skin blister would you expect to find inflammatory cells in there?
Very few
What type of tissue does abscess occur in?
Solid
In an abscess what type of necrosis is in the centre?
Liquefactive
What type of problems can you get it exudate pours into serous cavities?
- ascites
- pleural effusion
- pericardial effusion
which acute inflammatory condition is described as having a bread and butter appearance ?
Pericarditis
