Acute Inflammation Flashcards
What are the cardinal signs
Rubor - redness
Tumor - swelling
Calor - heat
Dolor - pain
What are the clinical signs of acute inflammation?
Vasoconstriction -> vasodilation -> increased permeability
What are the 2 types of interstitial fluid?
1) exudate - increased vascular permeability. Protein rich fluid. Occurs in inflammation
2) vascular permeability unchanged. Fluid movement due to increased capillary hydrostatic pressure and reduced capillary oncotic pressure. Occurs in heart failure/hepatic failure/renal failure
How do capillaries become more permeable?
Retraction of endothelial cells
Direct injury
Leucocyte dependent injury
How is the vascular phase effective?
Interstitial fluid dilutes toxins
Exudate delivers proteins e.g. fibrin which forms a mesh, limiting the spread of toxin
Describe the stages of how neutrophils escape capillaries
Margination
Rolling
Adhesion
Emigration/diapedesis
What is the function of selectins?
Expressed on activated endothelial cells (activated by chemical mediators)
Responsible for ‘rolling’
What are the functions of integrins?
Found on neutrophil surface
Change from low to high affinity state
Responsible for ‘adhesion’
How can neutrophils be identified in histology?
Appearance of trilobed nucleus
What is chemotaxis?
Movement along an increasing chemical gradient of chemoattractants
How do neutrophils contribute to acute inflammation?
Phagocytosis, phagosome fuses with lysosome, produce secondary phagolysosome.
Release inflammatory mediators
What is opsonisation?
This is how neutrophils know what to phagocytose
Toxins covered in C3b and Fc
Receptors for C3b and Fc on neutrophil surface
How is the cellular phase effective?
Removal of pathogens and necrotic tissue
Release inflammatory mediators
Give some examples of local complications of acute inflammation
Exudate - compression of organs e.g. cardiac tamponade.
Loss of fluid e.g. burns
Pain - muscle atrophy, psycho-social consequences
Give some examples of systemic complications of acute inflammation
Fever - some inflammatory mediators are pyrogens, act on hypothalamus to alter temperature
Leucocytosis - increased production of white cells.
Acute phase response - malaise, reduced appetite, altered sleep, tachycardia - induces rest.
