Acute Inflammation 2 Flashcards
What is the name of inflammation at these various sites? Peritoneal cavity Meninges Appendix Lungs Pleural cavity
Peritonitis Meningitis Appendicitis Pneumonia Plearisy
What do neutrophils do?
Recognise foreign antigen
Move towards it - chemotaxis
Adhere to the organism
They are mobile phagocytes
Phagocytose and destroy foreign antigen
What do the granules do that neutrophils release the contents of?
Possess oxidants - H202 and enzymes (proteases )
When does a neutrophil die?
When granule contents are released
What is pus?
Produced by neutrophils - its a soup of fluid, bits of cells, organisms, endogenous proteins
What is fibrinogen?
PLasma protein - coagulating factor forming fibrin which clots exudate, localises inflammatory process
What plasma protein is responsible for humoural immune response?
Immunoglobulins
What does humoural mean?
Relates to the immune response that involves the release of antibodies in circulating bodily fluids
Where are the mediators of acute inflammations?
Molecules on endothelial cell surface membrane - released from cells, molecules in the plasma
What are endothelial cells?
Line the walls of blood vessels
What the collective effects of mediators?
Vasodilation Increased permeability Neutrophil adhesion - mediators from different cells adhere because of their mediators Chemotaxis Itch and pain
Describe the action of adhesion molecules that appear on endothelial cells
Help neutrophils stick
ICAM - 1
Describe the function of P-Selectin
Interacts with neutrophil surface
What releases histamine?
Mast cells beside vessels, platelets, basophils
When is histamine released?
As a result of local injury
What is the effect of histamine?
Vasodilation, increases permeability, acts via H1 receptors (histamine receptors) on endothelial cells
What is another name for serotonin?
5 - hydroxytryptamine
Where is seratonin released from?
Platelets, when they degranulate in coagulation
Vasoconstriction - to keep useful materials in the correct place
What are the immediate systemic effects of inflammation?
Pyrexia - endogenous pyrogens from white blood cells act centrally
Feel unwell - malaise, anorexia, nausea, abdominal pain, vomiting in chilrdren
Neutrophilia - raised WBC count
What are the long term effects of inflammation?
Lymphadenopathy - lymph node enlargements
Weight loss - catabolic process
Anaemia
Describe what suppuration is
Pus formation
Pyogenic membrane surrounds pus (capillary sprouts neutrophils, fibroblasts - walls off pus)
What is an abscess?
Collection of pus under pressure
What is a multiloculated abscess?
Pus burts through the pyogenic membrane - forms new cavities
What is empyema
- pus in a hollow viscus (gall bladder, pleural cavity)
What is pyaemia
Discharge of pus to the blood stream
What is organisation?
Healing and repair - leads to fibrosis and formation of scar
Granulation tissue characteristic
What is granulation tissue?
Universal patch
It is formed of new capillaries
Fibroblasts and collagen
Macrophages
Describe the outcome of dissemination
Spreads to the bloodstream - patient is now described as septic
What is the difference between bacteraemia and septicaemia?
Bacteria in blood versus the growth of bacteria in blood
What is toxaemia?
Toxic products in the blood
How do you calculate cardiac output?
Stroke volume multiplied by heart rate
How can you calculate blood pressure?
Cardiac output multiplied by systemic vascular resistance
Define SVR
An index of arteriolar constriction throughout the body, calculated by dividing the blood pressure by the cardiac output.
What is the effect of systemic infection?
Shock - inability to perfuse tissue
What is the clinical picture of early septic shock
Peripheral vasodilation Tachycardia Hypotension Often pyrexia Sometimes haemorrhagic skin rash - blood vessels leaking
What is the effect of bacterial endotoxin?
Interleukin- 1 is released - acts on hypothalamus - pyrexia
What is the effect of prostglandins? (archidonic acid metabolite)
Histamine effects and inhibit inflammatory cells
Thromboxan A2 - promotes platelet aggregation and vasoconstriction
What is a leukotriene? (archidonic acid metabolite)
Any substance which is derived from a leucocyts (white blood cell)
Are leukotrines vasoactive?
Yes, they increase permeability and constrict smooth muscle
What is the effect of omega 3 polyunsaturated fatty acids?
Decreases synthesis of archidonic acid derived inflammatory mediators
What is the function of platelet - activating factor?
Produced especially by mast cells and basophils, It is a lipid molecule responsible for platelet aggregation degranulation, releasing factors such as histamine and seratonin
What are cytokines and chemokines?
Small molecules produced by macrophages, lymphocytes , endothelium in response to inflammatory stimuli
They attract inflammatory cells
What is the function of NO?
Released by various cells, responsible for smooth muscle relaxation, anti-platelet, regulate functional activity, growth and death of many cell types including macrophages, T lymphocytes, antigen presenting cells, mast cells, neutrophils and natural killer cells. It regulates leukocyte recruitment to inflammatory focus
What are the effects of oxygen free radicals and what are their names?
H2O2, OH-, O2-
Released by neutrophils on phagocytosis
Amplify other mediator effects
What are the different plasma enzymes involved?
Blood coagulation pathways - clotting fibrinogen in exudate
Fibrinolysis - breaks down fibrin maintaining blood supply. The breakdown products are vasoactive
Kinin system - bradykinin is responsible for pain
Complement cascade -
Increase permeability, chemotaxis, phagocytosis, cell breakdown
What are the key effects of the mediators?
Vasodilation and constriction Altered permeability Neutrophil adhesion Chemotaxis Itch and pain
What is the pathogenesis of septic shock?
There is a release of chemical mediators from cells into plasma
Mediators cause vasodilation
Vasodilation results in loss of systemic vascular resistance
This results in catecholamine (adrenaline and noradrenaline release)
Tachycardia follows to maintain cardiac output
Bacterial endotoxins are released (interleukin- 1 - pyrexia)
The increased heart rate is insufficient to maintain cardiac output during septic shock, what is the effect of this?
Blood pressure drops due to reduced SVR
There is a reduced perfusion of tissues, hypoxia and loss of cell tissue and organ function
What is the outcome of septic shock
Rapidly fatal
Tissue hypoxia
Haemorrhage
Requires immediate intervention and support
What are the outcomes of acute inflammation?
Resolution Suppuration Organisation Dissemination Chronic inflammation
