Abstract: A multiple flow-based microfluidic cell culture system that emulates mammalian physiology is provided. Tissue-mimicking cell cultures are connected by flow within a physiologically meaningful arrangement so that the pharmacokinetics of various agents to be tested in the system emulate in vivo conditions. The system includes at least two organ tissue modules, each organ tissue module including a first chamber containing an organ tissue cell, the first chamber including an inlet and an outlet for flow of an organ tissue cell-specific culture medium; a second chamber including an inlet and an outlet for flow of a blood material; and a semi-permeable membrane separating the first and second chambers. The flow of blood material through each organ tissue module is interconnected and the flow of tissue-cell specific culture medium is directed to a single organ tissue module.