Humoral immunity<span> or humoural </span>immunity<span> is the aspect of </span>immunity<span> that is </span>mediated<span>by macromolecules found in extracellular fluids such as secreted </span>antibodies<span>, complement proteins, and certain antimicrobial peptides. Humoral </span>immunity<span> is so named because it involves substances found in the humors, or body fluids.</span>
The answer is diffusion.
Facilitated diffusion is a process by which molecules are transported across the plasma membrane with the help of membrane proteins.
