These alveoli are the smallest types of lung tissue, and one of the most important. In addition to being the primary means by which oxygen enters and carbon dioxide escapes the bloodstream, these small pouches of air are also the reason why the lungs do not totally collapse when a person breathes out. This is because they contain a cell that secretes a special chemical to lower the surface temperature to prevent lung collapse. The alveoli also contain other cells that secrete chemicals to attack and remove any foreign objects in the lungs, such as dust, dirt and other debris.
In addition to making up alveolar sacs, alveoli also form alveolar ducts. It is estimated that there are more than 300 million alveoli in the human lungs, all of which are located in either alveolar ducts or sacs that are found at the end of the smaller passageways, or bronchioles, in the lungs.
SHORT ANSWER:
Alveolar sacs contain tiny pouches called alveoli, whose primary function is gas diffusion. These clusters of alveoli have thin walls that allow oxygen to pass easily from the lungs into the bloodstream and carbon dioxide to flow from the blood to the lungs so it can exit the body.
Hello!
The amount of water in a river varies for each particular area. Whether the area has been receiving rainfall or a drought.
Seasons also play a role; if it's Spring, you may receive more rainfall and have a higher water levels. If it's Summer, you may experience a drought, causing lower water levels.
Although that was not very much information, I thought I'd provide a small bit of information. Hope it helps. :)
The answer is true you can find these things out by DNA abd chromosomes
Cervix
Janine recently had surgery on the neck, or narrow lower portion, of her uterus. Janine's surgery was performed on the cervix.
The cervix is the narrow neck-like passage that forms the lower portion of the uterus in the human female reproductive system. The cervix joins the vagina and uterus and it is mainly made up of fibromuscular tissue. The two major parts of the cervix are ectocervix and endocervix. During menstrual cycle, the cervix opens a bit to allow the passage of menstrual flow. The cervix also dilates largely to allow the passage of baby during childbirth.
