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.
The most common causes of anemia are: 1  loss of blood through surgery, accidents and other causes. 2  conditions such as chronic kidney disease, liver disease, cancer, HIV/AIDS. 3  not enough iron, vitamin B12 or folic acid. 4  a poor diet. 5  diseases that destroy red blood cells, such as sickle cell anemia.