Simplify the following text for a Grade 14 native English-speaking person.
Original: Chemical factors produced during inflammation ( histamine , bradykinin , serotonin , leukotrienes also prostaglandins ) sensitize pain receptors , cause vasodilation of the blood vessels at the scene , and attract phagocytes , especially neutrophils .
Simplified: Chemical factors produced during inflammation attract phagocytes , especially neutrophils .