acute inflammation 1 Flashcards
acute inflammation
series of protective changes occurring in living tissue of higher organisms as a response to injury. The function of these changes is to produce a fundamental response that maintains the integrity of the organism.
cardinal signs of inflammation
rubor calor tumor dolor loss of function
rubor
redness
calor
heat
tumor
swelling
dolor
pain
why there is loss of function with inflammation.
prevents any more damage to area injured.
aetiology
what causes a disease
aetiology of acute inflammation
microorganisms mechanical chemical physical dead tissue hypersensitivity
microorganisms causing acute inflammation
bacteria, fungi, viruses, parasites. These all cause infection.
mechanical causes of acute inflammation
all trauma even if sterile will cause acute inflammation.
chemical causes of acute inflammation
acid or alkali will upset pH
bile and urine will cause irritation when in the wrong place.
physical causes of acute inflammation
caused by extreme conditions. eg. heat-sunburn cold-frostbite ionising radiation
dead tissue causing acute inflammation
cell necrosis irritates adjacent tissue
how does hypersensitivity cause acute inflammation?
it initiates an exaggerated immune response
benefits of acute inflammation
- rapid response to non-specific insult.
- cardinal signs and loss of function provide transient protection of inflammed area.
- allows neutrophils access area to provide an immune response.
steps in acute inflammation
- changes in vessel radius which causes changes in flow
- change in the permeability of the vessel wall; exudation
- movement of the neutrophils from the vessel to the extra vascular space.
local changes in vessel radius and blood flow
- transient arteriolar constriction
- local ateriolar dilatation
- relaxation of vessel smooth muscle
exudation
net movement of plasma from capillaries to extravascular space
proteins in exudate
fibrinogen and immunoglobulin
oedema
accumulation of fluid in the extravascular space
change in laminar flow during inflammation
normally the WBCs flow in the centre of the blood vessels as they are the biggest, the RBCs flow on the outside. However during inflammation the RBCs group together to for rouleaux so they are found in the centre and the WBCs flow is marginated.
phases of emigration of neutrophils
margination- neutrophils move to endothelial aspect of lumen
pavementing- neutrophils adhere to endothelium
emigration
neutrophils squeeze between endothelial cells (active process) to extravascular tissues.
