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Unformatted text preview: Tissue compliance is generally low; that is, small increases in tissue volume as occurs during states of enhanced filtration or lymphatic blockage result in dramatic increases in PT. The rise in PT that occurs with increased interstitial fluid volume decreases the hydrostatic gradient across the capillary thereby limiting filtration. Capillary Plasma Oncotic Pressure (PC )
Because the capillary barrier is readily permeable to ions, the osmotic pressure within the capillary is principally determined by plasma proteins that are relatively impermeable. Therefore, instead of speaking of "osmotic" pressure, this pressure is referred to as the "oncotic" pressure or "colloid osmotic" pressure because it is generated by colloids. Albumin generates about 70% of the oncotic pressure. This pressure is typically 25-30 mmHg. The oncotic pressure increases along the length of the capillary, particularly in capillaries having high net filtration (e.g., in renal glomerular capillaries), because the filtering fluid leaves behind proteins leading to an increa...
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- Fall '07
- Hydrostatic Pressure