Dictionary

nares The nostrils.

narcotic 1 A drug that causes insensibility or stupor. A narcotic induces narcosis, from the Greek “narke” for “numbness or torpor.” 2 A drug such as marijuana which is subject to regulatory restrictions comparable to those for addictive narcotics.

narcolepsy A neurological disorder that is marked by the recurrent, sudden, uncontrollable compulsion to sleep. Narcolepsy is often associated with cataplexy (a sudden loss of muscle tone and paralysis of voluntary muscles associated with a strong emotion), sleep paralysis (immobility of the body that occurs in the transition from sleep to wakefulness), hypnagogic hallucinations (presleep…

nanism See dwarfism.

nails, white spots on the See jogger’s nails.

nails, ringworm of the See onychomycosis.

nail-patella syndrome A hereditary condition that is characterized by abnormally formed or absent nails and underdeveloped or absent kneecaps. Abbreviated NPS. Other features of NPS include iliac horns; elbow abnormalities that interfere with full range of motion (pronation and supination); glaucoma; and kidney disease that resembles glomerulonephritis, which can be progressive and lead to kidney…

nail furrows Transverse lines or grooves across the fingernails; transverse depressions in the nail plate caused by temporary cessation of cell division in the proximal nail matrix. The condition may be caused by local disease of the nail fold, physical trauma to it, or a systemic insult, such as an illness or a drug as,…

nail fungus See onychomycosis.

nail care Care of the fingernails and toenails. Many nail problems are due to poor nail care. Recommendations for maintaining nail health include keeping nails clean and dry to keep bacteria and other infectious organisms from collecting under the nails, cutting nails straight across with only slight rounding at the tip, using a fine-textured file…

nail 1 A piece of metal that is used to hold two or more pieces of bone together (for example, after a fracture). 2 The horny plate on the end of the finger (fingernail) or toe (toenail). Each nail has a body, lateral nail folds on its sides, a lunula (the little moon-shaped feature at…

nadir The lowest point. The nadir may refer, for example, to the lowest blood count after chemotherapy or the lowest concentration of a drug in the body.