Valve

Engineering definition

A mechanical device used to control the flow of fluids, e.g., liquids or gases, within a system. Knobs are used to vary the flow through the valve (e.g., garden hose bib).

Medical definition

Folds of tissue in vessels or hollow organs that prevent backward flow or reflux. These membranes ensure one-way movement of material.

Confusion

An engineer may not realize that anatomical valves cannot adjust the rate of flow. They are instead what are known as check valves.