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Other countercurrent exchange circuits where the incoming and outgoing fluids touch each other are used for retaining a high concentration of a dissolved substance or for retaining heat, or for allowing the external buildup of the heat or concentration at one point in the system. Countercurrent exchange circuits or loops are found extensively ...
A countercurrent exchange system is utilized between the venous and arterial capillaries. Lowering the pH levels in the venous capillaries causes oxygen to unbind from blood hemoglobin because of the Root effect. This causes an increase in venous blood oxygen partial pressure, allowing the oxygen to diffuse through the capillary membrane and ...
A countercurrent mechanism system is a mechanism that expends energy to create a concentration gradient. It is found widely in nature and especially in mammalian organs. For example, it can refer to the process that is underlying the process of urine concentration, that is, the production of hyperosmotic urine by the mammalian kidney.
A countercurrent exchange system is utilized between the venous and arterial capillaries. By lowering the pH levels in the venous capillaries, oxygen unbinds from blood hemoglobin . This causes an increase in venous blood oxygen concentration, allowing the oxygen to diffuse through the capillary membrane and into the arterial capillaries, where ...
In a countercurrent flow system, air (or, more usually, the water containing dissolved air) is drawn in the opposite direction to the flow of blood in the gas exchanger. A countercurrent system such as this maintains a steep concentration gradient along the length of the gas-exchange surface (see lower diagram in Fig. 2).
A comparison between the operations and effects of a cocurrent and a countercurrent flow exchange system is depicted by the upper and lower diagrams respectively. In both it is assumed (and indicated) that red has a higher value (e.g. of temperature) than blue and that the property being transported in the channels therefore flows from red to blue.
For a balanced counter-current flow heat exchanger (balanced meaning =, which is a scenario desirable to enable irreversible entropy production to be reduced given sufficient heat transfer area): ϵ = N T U 1 + N T U {\displaystyle \epsilon \ ={\frac {NTU}{1+NTU}}}
This allows for a countercurrent exchange system whereby the medulla becomes increasingly concentrated, but at the same time setting up an osmotic gradient for water to follow should the aquaporins of the collecting duct be opened by ADH.