National Academy of Sciences A nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology, and to their use for the general welfare. Abbreviated NAS. The US Congress granted the NAS a charter in 1863 with the authority that requires it to advise the federal…
nasopharynx The area of the upper throat that lies behind the nose. See also oropharynx.
nasogastric tube A tube that is passed through the nose and down through the nasopharynx and esophagus into the stomach. Abbreviated NG tube. It is a flexible tube made of rubber or plastic, and it has bidirectional potential. It can be used to remove the contents of the stomach, including air, to decompress the stomach,…
nasogastric Referring to the passage from the nose to the stomach. Abbreviated NG.
naso- Prefix referring to the nose, as in nasogastric tube (a tube that is passed through the nose and to the stomach).
nasal septum, perforated A condition in which the dividing wall between the two main nasal passages has been eroded away, resulting in a communication between the passages. Perforated nasal septum can be caused by a number of conditions, including repeated inhalation of cocaine and other harmful drugs. It can usually be repaired with surgery.
nasal septum, deviated Failure of the nasal septum to be in the center of the nose and divide the nasal passages evenly. Deviation of the nasal septum may be congenital (present at birth) or acquired (occur later). The major problem it causes is airway obstruction. A deviated septum can be corrected with surgery.
nasal septum The dividing wall that runs down the middle of the nose, separating the two nasal cavities, each of which ends in a nostril. The nasal septum is composed of bone, cartilage, and membranes.
nasal polyp A growth or protrusion of tissue in the nose or sinuses. Nasal polyps may produce no symptoms or may lead to obstruction of the nasal passages, sinus infection, and a decreased sense of smell. Nasal polyps are almost always benign. Treatment can involve medications or surgery.
nasal passage A channel for airflow through the nose. The walls of the nasal passages are coated with respiratory mucous membranes, which contain innumerable tiny hair-like cells that move waves of mucus toward the throat. Dust, bacteria, and other particles inhaled from the air are trapped by the mucus in the nose, carried back, swallowed,…
nasal decongestant A drug that shrinks the swollen membranes in the nose, making it easier to breathe. Decongestants can be taken orally or as nasal drops or spray. Nasal decongestants should not be used for more than 5 days in a row without a physician’s consent. When nasal decongestants are used for a long time…
nasal Having to do with the nose.