Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «N»:
Natriuresis: The excretion of an excessively large amount of sodium in the urine. Natriuresis is similar to diuresis (the excretion of an unusually large quantity of urine), except that in natriuresis the urine is exceptionally salty. Natriuresis occurs with some diuretics and diseases (as of the ad...
Natriuretic: Causing natriuresis, the excretion of an excessively large amount of sodium in the urine.
A hybrid of the Latin natrium = sodium and the Greek ouresis = a making water....
Natriuretic peptide: One of the peptides that causes natriuresis, the excretion of an excessively large amount of sodium in the urine. The natriuretic peptides are produced by the heart and vasculature:
A-type natriuretic peptide is secreted largely by the atrial myocardium in response to dilatati...
Natural family planning
Natural family planning: Also known as fertility awareness, periodic abstinence and the rhythm method, this approach entails not having sexual intercourse on the days of a woman's menstrual cycle when she could become pregnant or using a barrier method (such as a condom, the diaphragm or a cervical ...
Natural immunity: Immunity that is naturally existing, Natural immunity does not require prior sensitization to an antigen. See: Innate immunity....
Natural killer cell
Natural killer cell: A cell that can react against and destroy another cell without prior sensitization to it. Natural killer (NK) cells are part of our first line of defense against cancer cells and virus-infected cells.
NK cells are small lymphocytes that originate in the bone marrow and develop ...
Menopause, natural: Natural menopause occurs when the ovaries naturally
decrease their production of the sex hormones estrogen and progesterone; there are
no menstrual periods for 12
consecutive months; and no other biological or physiological cause can account
Menopause is the end of...
Natural pacemaker: The natural pacemaker of the heart is the sinus node, one of the major elements in the cardiac conduction system, the system that controls the heart rate. This stunningly designed system generates electrical impulses and conducts them throughout the muscle of the heart, stimulatin...
Naturalistic study: A type of study in which the researcher very carefully observes and records some behavior or phenomenon, sometimes over a prolonged period, in its natural setting while interfering as little as possible with the subjects or phenomena.
In medical research, a naturalistic study us...
Nature (journal): The name of a venerable British scientific journal that has over the past century or so published much of importance to medicine and the biomedical sciences.
There are now, in fact, eight publications in the Nature family of journals:
The weekly Nature (founded in 1869), and
Naturopath: A person who practices naturopathy, a drugless system
of therapy based on the use of physical forces such as heat, water, light, air and
Naturopathic: Pertaining to naturopathy....
Naturopathic medicine: See: Naturopathy....
Naturopathy: A system of therapy based on
preventative care, and on the use of heat, water, light,
air, and massage as primary therapies for disease. Some
naturopaths use no medications, either pharmaceutical or
herbal. Some recommend herbal remedies only. A few who are
licensed to prescribe ma...
Nausea: Nausea, is the urge to vomit. It can be brought by many
causes including, systemic illnesses, such as influenza, medications, pain, and inner ear
disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever...