Dictionary

Body systems

Anatomy and the conditions of each body system, from the heart and lungs to the skin.

NADNicotinamide adenine dinucleotide, a helper molecule in cell energy; in charting, often "no acute distress".

NADHThe form of NAD that carries electrons and energy from food to the cell's energy-making machinery.

nail bedThe skin underneath a fingernail or toenail.

narisA nostril, one of the two openings of the nose; the plural is nares.

nasalHaving to do with the nose.

nasal cannulaA thin plastic tube with two short prongs that sit in the nostrils to give oxygen.

nasal cavityThe space inside the nose, behind the nostrils, through which air passes on its way to the throat.

nasal septumThe wall of cartilage and bone that divides the inside of the nose into right and left sides.

nasogastric decompressionRemoving air and fluid from the stomach through a nasogastric tube attached to suction.

nasopharynxThe top part of the throat, behind the nose and above the soft palate.

natriureticMaking the kidneys remove more sodium in the urine.

natriuretic peptideA hormone released by stretched heart muscle that makes the kidneys remove sodium and water and relaxes the blood vessels.

nausea and vomitingFeeling sick to the stomach together with throwing up.

necrosisThe death of cells or tissue in a part of the body.

necrotizing enterocolitisA serious illness, mainly of premature babies, in which part of the bowel becomes inflamed and its tissue begins to die.

neonatalRelating to a newborn baby, in the first 28 days after birth.

neonatal abstinence syndromeWithdrawal in a newborn who was exposed before birth to opioids or other drugs the mother took.

neonateA newborn baby in the first 28 days of life.

nephritisInflammation of the kidneys.

nephrolithiasisThe forming of stones in the kidney.

nephrologistA physician who specializes in the kidneys and their diseases.

nephronThe tiny filtering unit of the kidney, where blood is filtered and urine is made.

nephrotic syndromeA kidney disorder in which damaged filters let large amounts of protein pass from the blood into the urine.

nerveA cord-like bundle of fibers that carries signals between the brain or spinal cord and other parts of the body.

nervous systemThe brain, spinal cord and nerves, which together carry messages that control the body.

neural tubeThe hollow structure in an early embryo that develops into the brain and spinal cord.

neuroblastomaA cancer that starts in immature nerve cells, most often in an adrenal gland, in young children.

neurologicalRelating to the nervous system: the brain, spinal cord and nerves.

neuromuscularHaving to do with both nerves and muscles, or with the place where a nerve meets a muscle.

neuronA nerve cell: a cell that carries electrical and chemical signals through the nervous system.

neuropathyDamage to or disease of one or more nerves, most often the nerves of the hands and feet.

neurotransmitterA chemical that a nerve cell releases to pass a signal to another nerve, muscle or gland cell.

neurovascularHaving to do with both the nerves and the blood vessels of a body part.

neurovascular checkAn assessment of blood flow, feeling and movement in a limb below an injury, cast, splint or surgery.

neutropeniaA lower than normal number of neutrophils, the white blood cells that fight bacterial infection first.

neutrophilThe most common type of white blood cell, which is first to reach and destroy bacteria at a site of infection.

newbornA baby in the first 28 days of life.

nocturiaWaking up at night to urinate, more than once or more than is usual for the person.

noduleA small, firm, rounded lump of tissue that can be felt or seen, in or under the skin or in an organ.

non-Hodgkin lymphomaA group of cancers that start in lymphocytes, a kind of white blood cell, other than Hodgkin lymphoma.

normal sinus rhythmThe heart's normal rhythm, started by the sinoatrial (SA) node, regular and at 60 to 100 beats a minute in adults.

NSTEMINon-ST-elevation myocardial infarction: a heart attack that does not raise the ST segment on the ECG.

nucleic acidA large molecule, DNA or RNA, that carries genetic information in living cells.

nutrientA substance in food that the body needs for energy, growth and repair.

nutritionThe intake and use of food and its nutrients for energy, growth and repair of the body.

nutritional rehabilitationA planned, step-by-step return to healthy eating and body weight for a person who is malnourished.

nystagmusRapid, repeated movements of the eyes that the person cannot control, side to side, up and down, or in circles.