So, let's suppose this is the air pathogeway, the bronchiol of our lungs. These are the epithelial cells, as shown, and these are the microscopic pollen particles. Now, as the pollen particle moves, it can release these tiny particles, even smaller particles that our body labels as pathogenic. So these are basically seen as pathogenic antigens by our body. So these tiny antigens can diffuse across the epithelial cells and into the nearby tissue, where we have different types of wide blood cells. So bealympicides produce plasma cells and these plasma cells can recognize these antigens and begin to produce the corresponding antibody that binds to this antigen.