What is the reflection coefficient in Starling equation?
Staverman’s reflection coefficient, σ, is a unitless constant that is specific to the permeability of a membrane to a given solute. The Starling equation, written without σ, describes the flow of a solvent across a membrane that is impermeable to the solutes contained within the solution.
What is the revised Starling principle?
The Revised Principle highlights the role of oncotic pressure of small volumes of interstitial fluid within a sub-compartment surrounding the microvessels rather than the tissue’s mean interstitial fluid oncotic pressure.
How can an imbalance of Starling forces lead to Oedema?
Edema is defined as a clinically apparent increase in the interstitial fluid volume, which develops when Starling forces are altered so that there is increased flow of fluid from the vascular system into the interstitium.
Which Starling forces favor filtration?
Consequently, the hydrostatic pressure gradient highly favors outward filtration of water whereas the oncotic pressure gradient favors inward resorption of water.
Is oncotic and osmotic pressure the same?
The main difference between Osmotic Pressure and Oncotic Pressure is that osmotic pressure is the pressure needed to stop the net movement of water across a permeable membrane which separates the solvent and solution whereas oncotic pressure is the contribution made to total osmolality by colloids.
What is reflection coefficient physiology?
The reflection coefficient is used to correct the magnitude of the measured gradient to take account of the effective oncotic pressure . It can have a value from 0 to 1.
Why was the Starling hypothesis revised?
A revised Starling Principle, proposed by Michel and Weinbaum (independent research), suggested the Starling forces only be applied across the eGCX since it is now considered the molecular sieve for plasma proteins. When the eGCX is experimentally removed, the hydraulic permeability would rise dramatically.
What are the Starling forces for filtration?
Glomerular filtration depends on the same opposing forces that produce the exchange of fluids in every capillary in our body: these are hydrostatic pressure and oncotic pressure and together they are known as Starling’s forces.
How does Starling forces maintain normal fluid movement?
Starling s hypothesis states that the fluid movement due to filtration across the wall of a capillary is dependent on the balance between the hydrostatic pressure gradient and the oncotic pressure gradient across the capillary.
When calculating Starling forces which force is responsible for pushing fluid out of the capillaries and into the interstitial fluid?
Hydrostatic pressure is a force generated by the pressure of fluid on the capillary walls either by the blood plasma or interstitial fluid. The net filtration pressure is the balance of the four Starling forces and determines the net flow of fluid across the capillary membrane.
What is the new understanding of the Starling equation as applied to capillaries?