| airsickness | A condition resembling seasickness or other forms of motion sickness occurring in airplane or space flight as a result of erratic and continuous stimuli of the inner ear. (05 Mar 2000) |
|---|---|
| airspace | Pertaining to the portion of the lung distal to the conducting airways or bronchi; alveolar. (05 Mar 2000) |
| airspace-filling pattern | Cloudy to dense opacities, obscuring vascular markings, on chest radiographs. Synonym: airspace-filling pattern. (05 Mar 2000) |
| airtrapping | Slow or incomplete emptying of air from all or part of a lung on expiration; implies obstruction of regional airways or emphysema. (05 Mar 2000) |
| airway | 1. Any part of the respiratory tract through which air passes during breathing. 2. In anaesthesia or resuscitation, a device for correcting obstruction to breathing, especially an oropharyngeal and nasopharyngeal airway, endotracheal airway, or tracheotomy tube. (05 Mar 2000) |
| airway obstruction | Any hindrance to the passage of air into and out of the lungs. (12 Dec 1998) |
| airway pattern | Chest radiographic appearance of thickened bronchial walls, bronchiectasis, bronchiolitis, or acinar consolidation. (05 Mar 2000) |
| airway resistance | The opposition of the tracheobronchial tree to air flow: the mouth-to-alveoli pressure difference divided by the air flow. (12 Dec 1998) |
| airy | 1. Consisting of air; as, an airy substance; the airy parts of bodies. 2. Relating or belonging to air; high in air; aerial; as, an airy flight. "The airy region." 3. Open to a free current of air; exposed to the air; breezy; as, an airy situation. 4. Resembling air; thin; unsubstantial; not material; airlike. "An airy spirit." 5. Relating to the spirit or soul; delicate; graceful; as, airy music. 6. Without reality; having no solid foundation; empty; trifling; visionary. "Airy fame." "Empty sound, and airy notions." (Roscommon) 7. Light of heart; vivacious; sprightly; flippant; superficial. "Merry and airy." 8. Having an affected manner; being in the habit of putting on airs; affectedly grand. 9. Having the light and aerial tints true to nature. Source: Websters Dictionary (01 Mar 1998) |
| Airy disk | <microscopy> The image of a bright point object as focused by a lens system. With monochromatic light, it consists of a central point of maximum intensity surrounded by alternate circles of light and darkness caused by the reinforcement and interference of diffracted rays. The light areas are called maxima and the dark areas minima. The distribution of light from the centre to the outer areas of the figure was investigated mathematically by Sir George Airy. The diffraction disk forms a basis for determining the resolving power of an ideal lens system. The diameter of the disk depends largely on the aperture of the lens. The diffraction of light causing the Airy disk is a factor limiting the resolution of a well corrected optical system. The bright disk of light (surrounded by alternating dark and bright diffraction rings)that is formed by a perfect diffraction-limited lens, focusing an image of an infinitely small source of light. For a minute absorbing spot, the diffraction pattern is a dark Airy disk surrounded by brighter and darker diffraction rings. Since the Airy disk is the smallest unit that makes up the image of a luminous or absorbing object (formed by a properly corrected microscope lens in focus), the radius of the disk determines the limit of resolution of the microscope. (05 Aug 1998) |
| aisle | A lateral division of a building, separated from the middle part, called the nave, by a row of columns or piers, which support the roof or an upper wall containing windows, called the clearstory wall. Improperly used also for the have; as in the phrases, a church with three aisles, the middle aisle. Also (perhaps from confusion with alley), a passage into which the pews of a church open. Origin: OF. Ele, F. Aile, wing, wing of a building, L. Ala, contr. Fr. Axilla. Source: Websters Dictionary (01 Mar 1998) |
| aitiology | <study> A branch of knowledge concerned with the causes of particular phenomena, specifically a branch of medical science concerned with the causes and origins of diseases. The study of factors of causation or those associated with the causation of disease or abnormal body states. Origin: L. Aetiologia, Gr. Aitiologia. (09 Feb 1998) |