As patient "X" makes her way back home from China, she begins to cough and sneeze badly thinking it was from the man sitting next to her. Bacteria has entered her body through her nose and mucus; for now, everything is okay but it may be a problem if it gets to the brain.
Something was going on, so she visited the clinical laboratory to take some blood tests. Test results were not too positive. Pathogens have reached her brain, the brain's tissue is currently inflamed.
The green specks represent pathogens surrounding the inflamed brain. Phagocytes are part of the situation as well. The phagocytes work to maintain and destroy the foreign invader, causing the inflammation by destroying and ingesting them.