| NPO | nothing by mouth [Lat. nulla per os]; nucleus preopticus |
|---|---|
| NPP | nitrophenylphosphate; normal pool plasma; nucleus tegmenti pedunculopontinus |
| NPV | negative predictive value; pressure value; negative pressure ventilation; net present value; nuclear... |
| NRA | nitrate reductase; nucleus retroambigualis |
| NRGC | nucleus reticularis gigantocellularis |