TABLE 2.

Proposed definitions related to death by neurologic criteria

	Proposed actualized definition	Conceptual model correlate
Flow	Movement of blood detected by opacification of major brain* vessels (arteries and veins) in blood flow studies	Is there water in the hose?
Perfusion	Capillary-level flow in the target tissue (in this case brain, specifically brainstem)	Is water reaching the plant?
Function	Organized clinical brainstem neuronal function as manifest by consciousness and brainstem reflexes	Is the flower alive?

*Brain is defined as the combination of the cerebrum and the brainstem.

Proposed actualized definitions of the concepts of brain blood flow, perfusion, and function in the light of our new conceptual model. These actualized definitions put the emphasis on the physiologic differences between the three concepts to avoid potential misinterpretation or misnaming.