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Guilherme Mazui

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What is the Difference Between Oncotic and Hydrostatic Pressure?

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The difference between oncotic and hydrostatic pressure lies in their roles in fluid exchange between blood capillaries and tissues. Here are the key differences between the two:

  • Oncotic Pressure: This is a form of pressure exerted by proteins in blood plasma or interstitial fluid. It is also known as colloidal osmotic pressure and pushes fluid back into the blood capillaries. Oncotic pressure is typically 25-30 mmHg and increases along the length of the capillary, particularly in capillaries with high net filtration.
  • Hydrostatic Pressure: This is the force exerted by the blood confined within blood vessels or the heart. It is the pressure that drives fluid out of the capillaries and into the tissues. Capillary hydrostatic pressure (CHP) is the force that blood exerts against a capillary, and it is the primary force driving fluid transport between the capillaries and tissues.

In summary, oncotic pressure is the force that pushes fluid into the blood capillaries, while hydrostatic pressure is the force that pushes fluid out of the blood capillaries. These two pressures, along with other factors, determine the fluid flow in and out of blood capillaries and play a crucial role in maintaining proper fluid balance in the body.

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  • What is the Difference Between Oncotic and Hydrostatic Pressure?
  • Comparative Table: Oncotic vs Hydrostatic Pressure

    • Comparative Table: Oncotic vs Hydrostatic Pressure

    Here is a table comparing the differences between oncotic pressure and hydrostatic pressure:

    Feature Oncotic Pressure Hydrostatic Pressure
    Definition Oncotic pressure is a form of pressure that is exerted by proteins, such as albumin, in blood plasma. Hydrostatic pressure is a form of pressure that is exerted by the fluid in blood plasma.
    Direction Pushes fluid into the blood capillaries. Pushes fluid out of the blood capillaries.
    Role in Microcirculation According to Starling's principle, oncotic pressure is one of the forces that modulate capillary dynamics, determining the fluid flow into and out of blood capillaries. Hydrostatic pressure is another force that modulates capillary dynamics, determining the fluid flow into and out of blood capillaries.
    Net Filtration Pressure Oncotic pressure, along with hydrostatic pressure, determines the net filtration pressure, which is the total pressure that promotes filtration. Both oncotic and hydrostatic pressures contribute to the net filtration pressure, which is the total pressure that promotes filtration.
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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.