A substance, such as a soap or emulsifier, that reduces surface tension. Pulmonary surfactant is secreted by the alveoli in the lungs, preventing them from collapsing during exhalation, and is absent in babies born significantly prematurely. This deficiency causes breathing difficulties, and the infant needs artificial ventilation and the administration of an artificial surfactant.
A surface-active agent lining the alveoli (see ALVEOLUS) 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.
n. a wetting agent. Surfactants can be added to materials used in dentistry to reduce surface tension and so improve flow. Pulmonary surfactant, secreted by type II *pneumocytes, is a complex mixture of compounds (including lipids, protein, and carbohydrates) that prevents the air sacs (alveoli) of the lungs from collapsing by reducing surface tension. In its absence, as in the immature lungs of premature babies, *atelectasis and *respiratory distress syndrome will develop.
Naturally produced in the LUNGS by cells called pneumocytes, this substance is a mixture of phospholipids (see PHOSPHOLIPID) and LIPOPROTEINS. Present in ?uid lining the alveoli (see ALVEOLUS) in the lungs, their action helps maintain their patency. Premature babies may have a de?ciency of surfactant, a disorder which causes severe breathing diffculties – RESPIRATORY DISTRESS SYNDROME or hyaline membrane disease – and HYPOXIA. They will need urgent respiratory support, which includes oxygen and the administration (via an endotracheal tube) of a specially prepared surfactant such as beractant (bovine lung extract) or edfosceril palmitate.... pulmonary surfactant
Health Encyclopedia