Alveoli serve what function in the lungs?



Pulmonary alveoli are the tiny sacs inside the lungs that fill with air with each breath and facilitate the exchange of gas with the blood. According to HowStuffWorks, the oxygen concentration in the alveoli is high, relative to that of the surrounding tissues, which permits easy passage to the blood.

With each breath, air from outside the body is pulled down the trachea and into the lungs through a branching network of pipes called bronchioles. These bronchioles get progressively smaller until they terminate in the alveolar sacs. The sacs have very thin walls, and they are heavily vascularized, according to HowStuffWorks. Their thin walls permit oxygen to cross over into the blood that is delivered by the pulmonary arteries and permits waste gasses like carbon dioxide to escape into the air in the sac.

Once the exchange takes place, a process that lasts just fractions of a second per cycle, the waste air is expelled with exhalation and the oxygen-rich blood is free to pass back to the heart via the pulmonary veins. This gas-exchange process in the lungs takes place exclusively within the alveoli and is known as external respiration, as opposed to the internal respiration that takes place across the membrane of individual cells, notes HowStuffWorks.



Visitors Who Viewed This FAQs Also Viewed

What are fluorescent light fixture covers?

Fluorescent light fixture covers, also called lenses, are polycarbonate-plastic or acrylic pieces th..

What is the part of the atom that accounts for electricity?

According to Encyclopædia Britannica, the electron is considered the basic unit of electricity withi..

Where can you find an online list of sodium content in common foods?

The University of Maine provides an online list of sodium content in common foods. It is a comprehen..

How do you tell him to go out with you?

just ask him gently if he wants 2 go 2 lunch with u..

How fast is a 250cc ATV?

it depends on the model I assume. My Yamaha Bruin 250 will do about 51 mph top speed. My Honda 250r ..

What is reggie waynes fan club mailing address?

1428 Second Street Suite 300 Santa Monica, CA 90401 USA..

Friendly Links for World's Top 10 Famous Electronic Components Distributors
circuits price | circuit transistor | circuits price | ic igbt pdf | faqs hub | datasheet ic pdf | transistors circuits | your answer | pdf ic datasheet | transistor triac | datasheet pdf for you | circuits components |