Diagrams showing the burn wound geometry (left) and a cartoon representation of the mathematical model (right). Host cells are covered by a liquid layer known as the exudate, which is itself covered by dead (necrotic) tissue, except in the region of the excision where the exudate is exposed to the air. Bacteria and inhibitors exist in one of two states: free in the exudate or bound to the host cells, and can transition between these states by binding to and unbinding from the host cells. Both free and bound bacteria can divide; daughters of free bacteria enter the exudate, whereas some of the bound bacterial daughters remain bound to the surface, the rest entering the exudate. Bound bacteria may be consumed and destroyed (phagocytosed) by immune cells called neutrophils, while free bacteria and inhibitors may leak out of the wound (clearance) in the first twenty-four hours after the excision is made and before a scab forms over the exposed exudate.