Acute Inflammation Revised Flashcards
What is acute inflammation?
Protective responses to injury caused to tissue
Name the five cardinal signs of infection.
Rubor
Calor
Tumor
Dalor
Loss of function
Rubor=?
Redness
Calor=?
Heat
Tumor=?
Swelling
Dalor=?
Pain
List some of the microorganisms which cause acute inflammation.
Viruses
Bacteria
Fungi
Parasites
List some of the mechanical causes of acute inflammation.
Trauma
Surgery
Name some of the extreme conditions which can cause acute inflammation.
Frost bite
Sun burn
Ionising radiation
How can bile or urine cause acute inflammation?
If they are in an area of the body that they shouldn’t be
How can necrosis cause acute inflammation?
Dead tissue irritates other adjacent cells
Where does acute inflammation take place?
Microcirculation
Describe the components of the microcirculation.
Capillary beds which are fed by arterioles and drained by venules
What maintains the dynamic balance of the microcirculation?
Hydrostatic pressure
Colloid Osmotic pressure
Describe the response time of the microcirculation.
Very fast
What happens to blood flow if there is an increased radius of vessels?
Increased blood flow
What physical changes occur with an increase in vessel diamter?
Redness and heat produced
Which process takes place in response to increased permeability?
Exudation
?What happens in exudation?
Exudate is leaked
Describe the contents of exudate
High in protein
Plasma
Fibrinogen
Immunoglobulin
What can exudate cause?
Oedema
What happens to blood when there is fluid loss?
Increased viscosity
What happens to blood with increased permability?
Viscosity increases and rate of flow decreases
What is meant by margination of neutrophils?
Neutrophils move to endothelial aspect of lumen
What is meant by pavementing of neutrophils?
Neutrophils adhere to endothelium
What is meant by migration of neutrophils?
Neutrophils move in between endothelial cells
Which of the three is an active process:
Margination
Pavementing
Migration
Migration
What are some of the benefits of acute inflammation?
Quick response
Neutrophils destroy antigens
Name the four possible outcomes for acute inflammation.
Resolution
Suppuration
Organisation
Chronic inflammation
Describe what neutrophils do.
Recognise antigens and move towards it.
Attach to antigen.
Release granule contents and destroy antigen
What is in the granule contents of a neutrophil?
Oxidants and enzymes
What happens to the neutrophil after releasing their content?
Neutrophil dies
What can neutrophils produce?
Pus
What can pus do?
Spread inflammation
What is fibrinogen?
Coagulation factor
What does fibrinogen do?
Forms fibrin and clots exudate
Localises inflammatory process
What can mediators cause?
Vasodilatation
Increased permeability
Neutrophil adhesion
Chemotaxis
Itch and pain
What is the purpose of adhesion molecules on endothelial cells?
They help neutrophils to stick
Given an example of an adhesion molecule found on endothelial cells.
ICAM1
What does Pselectin do?
Interacts with neutrophil surface
Is an adhesion molecule
What can be releases in response to injury by mast cells?
Histamine
What can histamine do?
Causes vasodilatation, increased permeability
Which type of receptors does histamine act on?
H1 receptors
When is 5-hydroxytryptamine (serotonin)
released?
When platelets degranulate in coagulation
What can 5-hydroxytryptamine (serotonin) cause?
Vasoconstriction
Which cells can produce cytokines or chemokines in response to inflammatory stimuli?
Macrophages
Lymphocytes
Nitric oxide can be released by cells.
What does it do?
Causes smooth muscle relaxation
Oxygen free radicals can be released.
What can they do?
Amplify the effects of other mediators
What releases oxygen free radicals?
Neutrophils upon phagocytosis
What do blood coagulation pathways do?
Clot the fibrinogen in exudate
What happens in fibrinolysis?
Fibrin is broken down to help maintain the blood supply
What happens in a compliment cascade?
Active components stimulate increased permeability, chemotaxis, phagocytosis, cell breakdown.
Linked to immune system
What is the purpose of neutrophils adhering to cells?
Favours and inhibits acute inflammation
Pyrexia=?
Raised temperature
What are some of the immediate systemic effects of inflammation?
Pyrexia
Nausea
Vomiting
What would you see in blood results of someone with inflammation?
Raised WBC count
What are some of the longer term effects of acute inflammation?
Enlarged lymph nodes
Anaemia
Weight loss
What happens in supuration?
Pus formation
What surrounds pus?
Pyogenic membrane to block it off
What is in pus?
Dead tissue, organisms, exudate, neutrophils, fibrin, red cells, debris
What is the name given to a collection of pus under pressure?
Abscess
What is a multiloculated abscess?
When pus breaks through pyogenic membrane
What tissue is present in organisation?
Granulation tissue
What does organisation lead to?
Fibrosis and formation of a scar
What is granulation tissue made of?
New capillaries
Fibroblasts and collagen
Macrophages
What is dissemination?
Spread of inflammation/infection to the bloodstream.
Bacteraemia=?
Bacteria in blood
Septicaemia=?
Growth of bacteria in blood
Toxaemia =?
Toxic products in blood
What are some of the systemic effects of infection?
Shock
Tachycardia
Hypotension
Pyrexia (fever)
What is released in response to septic shock?
Bacterial endotoxin interleukin-1
How does interleukin-1 cause a fever?
Acts on the hypothalamus
What can reduced perfusion of tissues lead to?
Tissue hypoxia
Loss of cell tissue and organ function
What are some of the outcomes of septic shock?
Tissue hypoxia/ cell death
Haemorrhage
