| N.A. | numerical aperture |
|---|---|
| N.Acc. | Nucleus accumbens |
| N.b. | Nippostrongylus brasiliensis |
| n.c.a. | No carrier added |
| N.C.J. | needle catheter jejunostomy |
| N.C.S. | newborn calf serum |
| N.H.S. | National Health Service |
| N.I.C.U. | Newborn Intensive Care Unit |
| N.m | Neisseria meningitidis |
| N.P.H. | Normal Pressure Hydrocephalus |