Which Species Have Cocurrent Gas Exchange?

To increase the rate of gas exchange by diffusion, amphibians maintain the concentration gradient across the respiratory surface using a process called buccal pumping.

Do mammals have countercurrent gas exchange?

Introduction to Vertebrate Breathing

Compared with the latter groups, mammals and birds have much more lung surface area—helping to meet their far higher needs for gas exchange. The barrier between the blood and the air or water in the breathing organs is notably thin in mammals and thinnest in birds.

What animals have unidirectional respiration?

Unidirectional flow means that air moving through bird lungs is largely 'fresh' air and has a higher oxygen content. Therefore, in bird lungs, more oxygen is available to diffuse into the blood.