Acute Inflammation Flashcards
Define Acute inflammation
Series of protective changes occurring in living tissue as a response injury
What is a cutaneous abscess?
An abscess in the surface of the skin
What is rubor
Redness for white people
Darkenning for coloured
What is calor?
Heat
What is a tumor?
Swelling
What is dolor?
Pain
What causes acute inflammation?
Microbes - pathogens
Mechanical - trauma injury to tissue
Chemical- upset stable environment pH changes
Physical - extreme condition
Dead tissue- cell necrosis irritates adjacent tissue
Hypersensitivity - several classes of reaction
Where does the process of acute inflammation?
Localised to affect tissue
Take place in micro circulation
What is microcirculation?
It is a system of capillaries arterioles and venules
Drained by the lymphatic system
Relaying on hydrostatic and osmotic pressure for movement
What is exudation?
Change in vessel wall permeability
What are the steps in acute inflammation?
Change in vessel radius
Change in vessel permeability
Movement of neutrophils
Why does inflammation have observed reedness and heat?
Increased arteriolar radius increases local tissue blood flow
How does the radius of arterioles change during inflammation?
Transcient arteriolar constriction
Local arteriolar dialation
Relaxes smooth muscles in vessel
What does transient arteriolar constrcition mean?
Arterioles construct for a few moments due to mechanical pressure and as a protective mechanism
What is the triple response?
Flush
Flare
Wheal
What is increased permeability?
Localised vascular response
Microvascular bed
Endothelial leak
Locally produced chemical mediator
What is leaked in exudate?
Fluid rich protein in plasma including immunoglobulin and fibrinogen
What are the effects of exudation?
1) Oedema is formed
Accumulates and causes swelling
Swelling causes pain and reduced function
2) fluid loss increases viscosity
Flow rate reduces
How does normal laminar flow look?
Plasma
With white blood cells (neutrophils) in the middle surrounded by erythrocytes
How is the flow during inflammation?
Erythrocytes clump in the centre
White blood cells moves to the outsides (margination )
What is margination of white blood cells?
White blood cells move to the endothelial aspect of lumen
What are the phases of emigration?
Margination
Pavementing
Emigration
What is diapedesis?
Red blood cells follow the neutrophils out as a passive flow
What is emigration?
Neutrophils squeeze between endothelial cells (active process)
What is pavementing?
Neutrophils adhere to endothelium
How is inflammation resolved?
Inciting agents isolated
Macrophages eat debris
Epithelial suurfae regenerated
Exudate filters away
Vascular changes return to normal
Inflammation resolved
What are the outcomes of acute inflammation?
Resolution
Suppuration
Organisation
Chronic inflammation
What do neutrophils do?
Recognise forgiegn organism and move towards it via chemotaxis and adhere to it
Releases granules contains oxidants and enzymes like H2O2
DESTROY AND PHAGOCYTOSE
What are the consequence of neutrophil action?
Neutrophils die when granule contents are released
Forms a soup of fluids and endogenous proteins
Can extend to the tissue and promote inflammation
What do plasma proteins do in inflammation?
Fibrinogen - coagulation
Immunoglobulins for humoral repsonse
What mediates acute inflammation?
Molecules on the endothelial cell surface
Molecules released from cells
Molecules in the plasma
Molecule inside cells
What happens as a result of mediators?
Vasodilation
Increased permeability
Neutrophil adhesion
Chemotaxis
Itch and pain
What are cell surface mediators?
Adhesion molecules on the endothelial cells
Like ICAM-1
What do histamines do?
Cause vasodialtion and bring mast cells and platelets to the injured area
What does serotonin do?
Vasoconstriction
What do prostglandins do?
Promote histamine effects
Inhibit inflammatory cells
Promotes platelet aggregation (clustering)
Vasoconstriction
What are cytokines?
Molecules produced by macrophages and lymphocytes in response to inflammation
Causes pro and anti inflammatory responses based on the type of cytokine
Cell signalling molecule
What does nitric oxide do?
Smooth muscle relaxation
Anti platelet
What do oxygen radicals do?
Amplify other mediators
Who produces oxygen free radicals?
Neutrophils
What is microbial antigen signalling?
If a microbial antigen is present
It forms a concentration gradient to attract a neutrophil which forms inflammation
What type of immunity is acute inflammation ?
Innate
What is danger associated molecular pattern?
Substances released for particular stimuli
Causes cellular behaviour to ensure inflammation continues
How do microbes cause inflammation?
The antigens trigger molecular pathways which causes inflammatory cytokine production in cell nucleus
Why is fibrinolysis important?
Keeps clotting localiseed
What is pyrexia?
Raised temp
Why do we get pyrexia in inflammation?
Endogenous pyrogens released from WBC
It’s a CNS effect from the hypothalamus
What does neutrophilia mean?
More neutrophils in the blood
What happens if inflammation persists?
Constant production of wbc reuslts in lymphadenopathy
Weight loss
Anaemia
Whta is lymphadenopathy?
Regional lymph node enlargement
Why does inflammation cause weight loss?
Inflammation is a catabolic process and sues up energy hence causes weight loss
What are the outcomes of inflammation?
Pus build up
Dead Tissue dead cells and fibrin sit in pypgenic membranes
What are capillary sprouts?
They are capillary blood vessels which grow into sites of inflammation so red blood cells can be supplied
What is an abscess?
Collection of pus under pressure
Discharges pus and breaks the skin
Like a pimple
What is granulation tissue?
Capillary sprouts growing around the edge of abscess towards the centre in the pyogenic membrane
What is a multipculated abscess?
It discharges sideways to form new abscesses rather than out a
What is Pyaemia?
Pus in the blood instead of the surface
Whta are the stages of healing for acute inflammation caused by wounds?
Granulation Tissue formation
Helping and repair
Fibrosis
Scar formation
What is in granulation tissue?
New capillary
Fibroblasts
Macrophages
What is bacteraemia ?
Bacteria in the blood
What is septicaemia?
Growth pf bacteria in the blood
What is toxaemia?
Toxic products in blood
True or False
Bacteraemia is more common than septicaemia
True
What does shock mean?
Inability to perfuse tissue
What are the clinical signs of early septic shock?
Tachycardia
Hypotension
Pyrexia
Peripheral vasodilation
Why do we get the symptoms (low BP, high heart rate, vasodilation) during septicaemia shock?
Hormones for inflammation aren’t localised
Blood vessels dialate as a result of hormonal activity
Hence blood pressure decreases
Heart rate increase in an attempt to increase blood pressure
Why are young people likely to die from sepsis?
Their hearts are better
Hence their heart can handle high heart rates so they will seem fine till the very last moment whereas older people tend to gradually get worse
What are the outcomes of acute inflammation?
Resolution
Suppuration
Organisation
Dissemination
Chronic inflammation
What is dissemination?
Spread to organs and body
Why is septic shock bad?
We get Tissue hypoxia and consequently cell death
What is the organisation part of acute inflammation?
Universal patch
Formation of granulation tissue during helaing
