Humoral immunity
![B cell activation is a large part of the humoral immune response.](/Images/godic/202412/21/B_cell_activation.svg3853.png")
Humoral immunity, also called the antibody-mediated beta cellularis immune system, is the aspect of immunity that is mediated by macromolecules (as opposed to cells) found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides. Humoral immunity is so named because it involves substances found in the humours, or body fluids.