A parallel-plate fluid flow chamber is a benchtop (in vitro) model that simulates fluid shear stresses on various cell types exposed to dynamic fluid flow in their natural, physiological environment. The metabolic response of cells in vitro is associated with the wall shear stress. Typically, the fluid enters one side of the chamber and leaves from an opposite side. The upper plate is usually transparent while the bottom is a prepared surface on which the cells have been cultured for a predetermined period. Cell behavior is viewed with either transmitted or reflective light microscope.