There are two types of alveolar cells. The type I alveolar cells which lines the alveoli and much more abundant than type II alveolar cells. Then the type II alveolar cells lesser in number but functions differently than type I alveolar cells. Type II alveolar cells secrete surfactant (composed of lecitin and sphingomyelin) for the lungs. Surfactant reduces the surface tension inside the alveoli, preventing alveolar consolidation. This is important as babies with dysfunctional type II alveolar cells (usually preterm babies less than 32 weeks age of gestation) will have respiratory distress syndrome in the absence of surfactant.
Answer:
your arteries that are connected to your lungs are also connected to your heart and then you need to be in the vena cava which are connected to your heart as well so you need the veins
the answer would be D!;
every object attracts every other object in the universe, with a force that increases as the objects' masses increase and the distance between them decreases.
Explanation:
<em>Beakers are the standard vessel used in chemistry. They come in all sizes including 5 milliliter (ml) flasks and flasks of many liters (L). Much like a cup or a mug, they consist of a cylinder, usually glass, with a flat bottom made to hold liquid. Beakers may or may not have a pour spout although they usually do.</em>
<em>hope this answer will help you!!!!!</em>
