An agent that acts on the surface to reduce interfacial surface tension between two liquids or between a liquid and a solid.
A fat-containing protein in the respiratory passages which reduces the surface tension of pulmonary fluids and contributes to the elastic properties of pulmonary tissue.
Surface active agent capable of breaking the surface tension of particles.
Surface active agents; compounds that have an affinity for fats (hydrophobic) and water (hydrophilic) and so act as emulsifiers, e.g. soaps and detergents. Used as wetting agents to assist the reconstitution of powders, including dried foods, to clean and peel fruits and vegetables, also in baked goods and comminuted meat products.
Acronym for surface active agent. Amphipathic molecules (i.e., molecules that contain both a polar and nonpolar domain) which, due to their unique properties, position themselves at interfacial regions (surfaces) such as an oil/water interface. When surfactants are dissolved above a certain critical concentration in either water or nonpolar solvents they may form micelles or reverse micelles, respectively. Surfactants are commonly used to solubilize cell membrane components and other hard to solubilize molecules.
An agent (normally present in the lungs as a phospholipid) that lowers surface tension; abnormal in the lungs of premature infants or in hyaline membrane disease.
A substance in the alveoli of the lungs which keeps the surfaces of the lungs wet and prevents lung collapse.
A compound that reduces the surface tension of a liquid so that another liquid can be mixed with it.
Substance that acts on a surface, especially certain lipoproteins that facilitate gaseous exchange in the alveoli by preventing alveolar collapse. Premature infants frequently experience respiratory distress because of a lack of surfactant.
Agent that lowers the surface tension of a liquid, such as mucous in the upper airway.
A fatty substance that is secreted by cells lining the alveoli (the lungs’ air sacs) and that coats the alveoli. Surfactant helps the air sacs expand, stretch, and maintain flexibility as a person inhales and exhales air. It also lowers the surface tension in the air sacs so pressure is evenly distributed among them.
A substance, such as a detergent, that reduces surface tension. A surfactant is secreted by the cells (pneumocytes) lining the alveoli of the lungs to prevent the alveolar walls from sticking together. In its absence, as in the immature lungs of premature babies and in some diseases, the lungs tend to collapse.
A surface-active agent lining the alveoli of the lungs, which plays an essential part in respiration by preventing the alveoli from collapsing at the end of expiration. Absence, or lack, of surfactant is one of the factors responsible for hyaline membrane disease, and it is now being used in the treatment of this condition by means of instillation into the trachea.
A surface-active agent that lowers surface tension (e.g., oils and various forms of detergents). Artificial surfactants may be given endotracheally to relieve respiratory distress.
A contraction of surface active agents; substances that allow oil and water to mix, or emulsify.
A compound produced by the alveoli in the lungs, which diminishes the surface tension of lung fluids, facilitating the exchange of gases and assisting in the preservation of lung tissue elasticity.
A compound that diminishes surface tension within a liquid. Pulmonary surfactant is discharged by the lung’s alveoli, preventing their collapse during exhalation. In considerably premature infants, the absence of surfactant can result in breathing challenges, potentially causing respiratory distress syndrome. In such instances, artificial ventilation and synthetic surfactant administration become necessary.