Surfactant is a complex substance containing phospholipids and a number of apoproteins. This essential fluid is produced by the Type II alveolar cells, and lines the alveoli and smallest bronchioles. Surfactant reduces surface tension throughout the lung, thereby contributing to its general compliance. It is also important because it stabilizes the alveoli.
Stagnant anoxia occurs when there is interference with the blood flow, although the blood and its oxygen-carrying abilities are normal. A common cause of general stagnant anoxia is heart disease or interference with the return of blood flow through the veins.
Recent studies, however, have found that anoxia is the cause of cerebral palsy in only between 3 and 12 percent of the cases. Approximately 85 percent of the brain damage related to cerebral palsy occurs prior to birth. Some of the prenatal causes may be prematurity, lack of proper nutrition, or virus.