Main difference – Hydrostatic vs Oncotic Pressure

Arteries carry oxygenated blood and nutrients to the metabolizing tissues of the body. This oxygenated blood travels with the capillary network within the tissues. The exchange the fluids in the blood capillaries is referred to as microcirculation. Hydrostatic and also oncotic pressure are the two species of driving pressures that are involved in the motion of fluids during microcirculation. The main difference between hydrostatic and also oncotic pressure is the hydrostatic pressure is the pressure that pushes the liquid out that blood capillaries conversely, oncotic pressure is the force that pushes the fluid into the blood capillaries. The overall interaction in between hydrostatic pressure and also oncotic push is explained by Starling’s principle.

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Key areas Covered

1. What is Hydrostatic Pressure – Definition, Mechanism, Function 2. What is Oncotic Pressure – Definition, Mechanism, Function 3. What space the Similarities in between Hydrostatic and Oncotic Pressure – rundown of common Features 4. What is the Difference in between Hydrostatic and Oncotic Pressure – compare of vital Differences

Key Terms: Arterial End, Blood Capillaries, Colloid Osmotic Pressure, Fluid, Hydrostatic Pressure, Microcirculation, Oncotic Pressure, Proteins, Venular End


What is Hydrostatic Pressure

Hydrostatic pressure refers to the force exerted through the liquid inside the blood capillaries against the capillary wall. It aids the activity of liquid from the blood capillaries come the interstitial fluid. The greatest hydrostatic press of the capillaries can be identified near the arteriole end. The lowest hydrostatic pressure occurs in ~ the venular end. Hydrostatic pressure at the blood capillaries is led to by the pumping press of the heart. Capillary network is presented in figure 1.


Figure 1: Capillary Network

The net filtration press is identified by the hydrostatic push inside the blood capillary and the osmotic pressure of the interstitial fluid. If the pressure difference is high, high filtration pressure have the right to be observed. At the arterial finish of capillaries, the hydrostatic press is 30 mmHg while osmotic push is 25 mmHg.

What is Oncotic Pressure

Oncotic pressure refers come the pressure exerted through albumin and also other proteins in the blood vessels. Since it is created by big molecules, oncotic pressure is likewise called colloid osmotic pressure. Generally, 20 mmHg pressure is generated by huge proteins inside the blood capillaries. Albumin contributes about 75% the the plasma oncotic pressure. Oncotic pressure reasons the movement of interstitial liquid into the capillaries at their venular end. Interstitial fluid has metabolic wastes and carbon dioxide indigenous the organization cells. Hence, oncotic pressure reasons the remove of wastes indigenous the tissues. It also helps to keep the liquid balance in the body. Capillary exchange is presented in figure 2.


Figure 2: Capillary Exchange

 The rise of the protein component in the interstitial fluid drops the oncotic pressure. This reduce the liquid movement right into the blood capillaries, causing edema. Edema is caused by the oncotic pressure of less than 11 mmHg. The excess protein in the interstitial fluid is removed by the flow of lymph.

Similarities between Hydrostatic Pressure and also Oncotic Pressure

Both hydrostatic and also oncotic push are involved in the motion of liquid in and also out of the blood capillaries.Both hydrostatic and oncotic pressures are used in microcirculation.

Difference between Hydrostatic and also Oncotic Pressure


Hydrostatic Pressure: Hydrostatic push refers to the pressure that is exerted by the liquid inside the blood capillaries versus the capillary wall.

Oncotic Pressure: Oncotic pressure refers come the pressure that is exerted by albumin and other protein in the blood vessels.


Hydrostatic Pressure: Hydrostatic push pushes fluids out of the blood capillaries.

Oncotic Pressure: Oncotic pressure pushes fluids right into the blood capillaries.


Hydrostatic Pressure: Hydrostatic press occurs together a result of the press of blood inside the capillaries.

Oncotic Pressure: Oncotic press occurs as result of proteins such as albumin, globulins, and fibrinogens within the blood capillaries.


Hydrostatic Pressure: Hydrostatic press is approximately 30 mmHg.

Oncotic Pressure: Oncotic push is roughly 20 mmHg.


Hydrostatic Pressure: Hydrostatic press is a kind of fluid pressure.

Oncotic Pressure: Oncotic press is a type of colloid pressure.


Hydrostatic Pressure: Hydrostatic press occurs in ~ the arterial finish of blood capillaries.

Oncotic Pressure: Oncotic push occurs at the venular end of blood capillaries.


Hydrostatic Pressure: Hydrostatic pressure rises filtration.

Oncotic Pressure: Oncotic pressure stays clear of fluid from leaving blood capillaries.


Hydrostatic Pressure: Hydrostatic press aids the it is provided of nutrient to the tissues of the body.

Oncotic Pressure: Oncotic pressure helps to eliminate metabolic wastes from the tissues.


Hydrostatic pressure and also oncotic pressure are two types of forces involved in the movement of fluid in the blood capillaries. Due to the pumping pressure of the heart, high hydrostatic push occurs in the arterial finish of the blood capillaries, leading to the activity of fluid from blood come the interstitial fluid. In ~ the venular end, huge proteins create a colloid push inside the blood capillaries. This reasons the motion of fluid into the blood capillaries indigenous the interstitial fluid. The main difference between hydrostatic pressure and also oncotic push is your mechanism and role.

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1. “Capillary Hydrostatic Pressure.” TutorVista.Com, obtainable here. 2. “Osmotic pressure and oncotic pressure.” Deranged Physiology, 27 June 2015, easily accessible here.

Image Courtesy:

1. “Capillaries” By national Cancer Institute, nationwide Institutes of health – (Public Domain) via Commons Wikimedia 2. “2108 Capillary Exchange” through OpenStax university – Anatomy & Physiology, Connexions net site, Jun 19, 2013. (CC through 3.0) via Commons Wikimedia