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1. Capillary filtration pressure
   • Length of capillary: 35mmHg at start - 20mmHg at end
2. Interstitial hydrostatic pressure
3. Colloid oncotic pressure (osmotic)
   • 25mmHg
   • Exerted by albumin, gamma-globulins
4. Interstitial oncotic pressure
   • Exerted by collagen, proteoglycans, hyaluronate

[Oedema][Lymphoedema]

Oedema

Abnormal accumulation of fluid in the intercellular spaces

May be

1. Transudate
   • Imbalance in hydrostatic pressures
   • Fluid: low protein <30g/l; specific gravity <1.020
2. Exudate
   • Inflammatory process
   • Fluid: high protein >30g/l; specific gravity >1.020
   • Classification - in terms of content or formation: (1) serous - pleural, pericardial, peritoneal (2) haemorrhagic - TB (3) Purulent - e.coli peritonitis (4) Fibrinous - pericarditis (5) Pseudomembranous

Classification

1. Exudate
2. Transudate