Acute inflammation Flashcards
What are the causes of acute inflammation
Micro-organisms (bacteria, fungi, viruses, parasites)
Mechanical (trauma, injury to tissue)
Chemical (Changes to pH, bile/ urine in the wrong places)
Physical (burn/ frostbite/ radiation)
Dead tissue (necrosis irritates hypersensitivity)
List the cardinal signs of acute inflammation
Redness, Pain, Heat, Swelling, Loss of function
Give the immediate effects of acute inflammation
Pyrexia - raised temperature
Unwell - nausea, lose appetite, abdominal pain
Neutrophilia - raised WBC count
Give the three main microvascular changes that occur
Change to blood vessel radius and blood flow
Increased permeability
Movement of neutrophils
Describe the sequence in which blood vessel radius increases
Short arterial constriction for protection
Local arterial dilation - excess blood in vessels
Relaxation of vessel smooth muscle
Increased radius > increased tissue blood flow . observed redness and heat
Describe what happens to blood vessels as an outcome of changes in permeability
Endothelial leak - fluid and proteins not held in vessel lumen
Leads to exudation
Describe what happens to neutrophils and RBC
WBC marginate to endothelium (pavement) and emigrate to the extravascular tissue
RBC aggregate in the centre of the lumen (rouleaux formation)
Describe suppuration
Pus formation
What surrounds the pus
Pyogenic membrane with ingrowth of granulation tissue
What is contained in pus
dead tissue, organisms, neutrophils, RBC, debris
Describe organistaion
Granulation tissue repairs wound
Leads to fibrosis and formation of a scar
What does granulation tissue contain
New capillaries (angiogenesis)
fibroblasts and collagen
macrophages
Describe exudation
Net movement of plasma from capillaries to extravascular space.
Fluid accumulates to form an oedema
Swelling > pain > reduce function
Describe dissemination
Inflammation spreads to bloodstream so patient becomes septic
What are the clinical symptoms of dissemination
Inability to supply tissue with blood Peripheral vasodilation High heart rate (tachycardia) Low BP (hypotension) Haemorrhagic skin rash - damaged vessels leak blood Tissue hypoxia - FATAL