Acute Inflammation Flashcards
What are 5 cardinal signs of acute inflammation?
Rubor (redness)
Calor (heat)
Tumor (swelling)
Dolor (pain)
Loss of function
What are 5 causes of acute inflammation?
Dead tissue (necrosis irritates tissue)
Pathogens
Chemical (acid, alkali)
Mechanical (tissue trauma)
Physical (extreme - sunburn/frostbite)
Where is the site of acute inflammation and why?
Micro circulation - capillary beds
Very fast to respond to stimuli
What happens to blood vessels in acute inflammatory response?
Radius increases so more blood flows to site
What happens to permeability of vessels in acute inflammatory response?
Increases - allows neutrophils and fluids to exit into extracellular space via EXUDATION
What is the effect of increased permeability of vessels and exudation?
Oedema is formed at the site of inflammation - causing tumour.
Fluid is lost from vessel which increases viscosity and slows blood flow
What happens to RBC’s and Neutrophils when in acute inflammatory response?
Blood flow changes, so RBC’s accumulate in the middle and Neutrophils migrate to the endothelium.
How do Neutrophils exit the cell in an acute inflammatory response?
Margination (move towards endothelium),
Pavement (bind to endothelium),
Emigrate (squeeze through endothelial cells and exit) and
Explain the process of resolution of acute inflammation
Inciting agent is destroyed and macrophages phagocytose waste. Epithelial regenerates and the exudates are filtered away. Vascularity returned to normal
What is chemotaxis?
Movement of a molecule/cell in response to increasing/decreasing conc. of a specific substance
Why is pus produces at a site of inflammation?
Neutrophils phagocytose products and release waste - fluid with cells and organisms
How can pus leas to a increased inflammatory response?
It may extend to other tissues and caused a response there too
What is the role of fibrinogen in the inflammatory response?
Plasma protein involved in Coagulation. It’s released with the other ‘fluid’ from the vessel. Forms clots and allows inflammation to have a protective barrier (localisation)
What type of mediators are involved in the acute inflammatory response?
- Molecules on surface membrane
- Molecules inside cell/plasma
- Molecules released from cell
What is the role of mediators found on the cells surface?
To make endothelium sticky so neutrophils can pavement/ adhere to it
What are the 5 collective effects of cell mediators?
Vasodilation
Permeability
Neutrophil adhesion
Chemotaxis
Itch and pain
What is the role of prostaglandins as a mediator?
Released from cell. Promote histamine effects and inhibits inflammatory cells
What is the role of histamine as a mediator?
Released from cell. cause vasodilation and increased permeability
What is the role of serotonin as a mediator?
Released from cells. causes vasoconstriction (to oppose the vasodilation effects of histamine)
What is the role of cytokines and chemokines as mediators?
Released from WBC’s and can have pro or anti-inflammatory effects
What is the role of NO and oxygen free radicals as mediators?
NO released from many cells and relaxes smooth muscle
O2 free radicals released from neutrophils (phagocytosis) and amplify the effects of other mediators
What are the 2 main inflammatory pathways? What do they do?
NFkB (nuclear factor kappa b)
MAPK (mitogen activated protein kinase)
Provoke cytokine production in nucleus, reducing inflammatory effect
What does JAK-STAT involve?
Translation of extracellular signals directly to molecular expression
When is plasma exudates and what is its roles (2)
First to be exudated. Has blood clotting factors to stop bleeding if present. Releases anti microbial to kill pathogens.
What are 3 outcomes of acute inflammation?
Suparation, organisation, dissemination
What does suparation involve?
The formation of pus, surrounded by pyogenic membrane. If under pressure, can form abscess
Empyema vs pyaemia
Pockets of pus in a body cavity vs release of pus into blood stream
What does organisation involve?
Formation of granulation tissue as response to acute inflammation which didn’t resolve and caused permanent damage as a scar
What does dissemination involve?
Pus being released to blood stream which may lead to sepsis
