diffusion.
Diffusion
fish gills. Blood in the feet of penguins Loop of Henle
Many fish use countercurrent exchange in their gills to transfer oxygen from the surrounding water into their blood. This system moves water flowing across the gills, in an opposite direction to the blood flowing in gill capillaries creating the maximum efficiency of gas exchange. This flow ensures that blood is always brought near to water having a higher oxygen concentration.
An organ in some animals that allows for the regulation of body temperature, such as a countercurrent heat exchanger in some fish.
Cromwell current
Cromwell current
The Loop of Henle
rental medulla
nephron loop
In the nephron loops, particularly in the juxtamedullary nephrons.
loop of henle,gills