Acute Inflammation 1 Flashcards
What is acute inflammation?
o Acute inflammation is a fundamental response maintaining integrity of an organism.
o It is a series or protective changes occurring in living tissue as a response to injury.
o It is a dynamic homeostatic response found in higher organisms.
What micro-organisms can cause acute inflammation?
- bacteria
- fungi
- viruses
- parasites
What are the mechanical causes of acute inflammation?
- trauma
- all injuries even sterile
- surgery
What are the chemical causes of acute inflammation?
- upset to pH
- irritation when bile and urine is in inappropriate place
What are the physical- extreme condition causes of acute inflammation?
- heat=sunburn
- cold=frostbite
- ionising radiation
Why does dead tissue cause acute inflammation?
cell necrosis irritates adjacent tissue
What are the cardinal signs of inflammation?
- tumour
- dolor
- rubor
- calor
- loss of function
What is the process of acute inflammation?
o Series of microscopic events
o Localised to affected tissue
o Take place in the microcirculation
o Result in the clinical symptoms and signs of acute inflammation- the cardinal signs.
What is involved in microcirculation?
- capillary beds fed by arterioles and drained by venules
- extracellular space and fluid and fluid and molecules within it
- lymphatic channels and drainage
What do starling forces control?
flow (fluid flux) across membrane
What is involved in dynamic balance?
hydrostatic and colloid pressures, compartments and physical constants
What is pathogenesis in acute inflammation?
o Changes in vessel radius- flow
o Change in the permeability of the vessel wall- exudation
o Movement of neutrophils from the vessel to the extravascular space.
What are the 3 stages in the triple response?
flush, flare and wheal
Describe the process of the triple response.
o Transient arteriolar constriction (few movements, probably protective)
o Local arteriolar dilatation (active hyperaemia)
o Relaxation of vessel smooth muscle (autonomic NS or mediator derived?)
Why is there an increase in blood flow?
o Poiseuille’s law= flow is proportional to radius to the power of 4
o Increased arteriolar radius causes increased local tissue blood flow
o Results in observed redness and heat
o A minute increase in the radius of a vessel will majorly increase the flow if no other factor changes.