However other regulatory processes rely on simple diffusion to maintain a balance.

Ascorbic acid is absorbed in the body by both active transport and simple diffusion.

Respiration and excretion are accomplished by simple diffusion.

Dissolved gases are brought to cells and enter the cells via simple diffusion.

Until recently, insect respiration was believed to occur entirely by simple diffusion.

What little oxygen their cells require can be absorbed by simple diffusion of air through their bodies.

It is not a simple diffusion of substances, but is active and requires energy use by the epithelial cells.

A clearance system based on simple diffusion would additionally lack the sensitivity to respond rapidly to deviations from homeostatic conditions.

It is a matter of simple diffusion doing work by dissipating the concentration gradient.

It turns out that flames in weightlessness overcome the lack of air currents by simple diffusion, or natural mixing.