[DOC] [TLE] Lungs and Respiratory System - KidsHealth [PAR] Oxygen is the most important for keeping us alive because body cells need it for 
energy and growth. ... Carbon dioxide is the waste gas that is produced when 
carbon is combined ... The lungs and respiratory system allow oxygen in the air to 
be taken into the ... Tiny hairs called cilia (pronounced: SIL-ee-uh) protect the 
nasal... [DOC] [TLE] How do air sacs in the lungs help with gas exchange - The Naked ... [PAR] Jan 14, 2007 ... In the wall of each balloon are tiny capillaries, which are very ... The blood from 
your heart gets pumped through your lungs, around the walls of these tiny air 
sacs first, ... vessels around the air sacs or alveoli, it exchanges carbon dioxide, ... 
And oxygen, which there's lots of in the air sac, comes out of the... [DOC] [TLE] Respiration - HyperPhysics [PAR] Gas exchange in the lungs takes place in the tiny air sacs called alveoli in the 
lungs. ... The lungs have millions of alveoli (Thibodeau & Patton) and each lies in 
contact with capillaries. ... Transfer of oxygen and carbon dioxide across the 
membranes occurs by diffusion, but the solubility of these gases in the material of 
the... [DOC] [TLE] Lungs, Lungs Information, Breathing Facts, News, Photos -- National ... [PAR] The waste gas carbon dioxide is produced as a byproduct and disposed of ... 
Central to the human respiratory system, they breathe in between 2,100 and ... of 
ever smaller tubes (bronchioles), which connect to tiny sacs called alveoli. The 
average adult's lungs contain about 600 million of these spongy, air-filled 
structures. [DOC] [TLE] Emphysema - Overview - NY Times Health - The New York Times [PAR] The alveoli are small sacs where oxygen is exchanged in the lungs. ... of both 
emphysema and chronic bronchitis, these conditions often develop together and 
... of air sacs at the end of the smallest airways (the bronchioles) in the lung. ... 
Until the late stages of the disease, oxygen and carbon dioxide levels remain 
normal. [DOC] [TLE] How it works - Respiration - Forms of Respiration, How Gases Move ... [PAR] that the human lungs and respiratory system are among the more complex ... The 
latter term describes an exchange of oxygen and carbon dioxide directly ... Lungs 
are composed of many small chambers or air sacs surrounded by blood 
capillaries. ... The reason is that humans have about 300 million gas-filled alveoli, 
tiny... [DOC] [TLE] What Is COPD? - NHLBI, NIH - National Heart, Lung, and Blood ... [PAR] These tubes end in bunches of tiny round air sacs called alveoli ... same time, 
carbon dioxide (a waste gas) moves from the capillaries into the air sacs. ... If this 
happens, the amount of gas exchange in the lungs is reduced. ... Most people 
who have COPD have both emphysema and chronic bronchitis. ... While 25 
million. [DOC] [TLE] Bird Respiratory System [PAR] The air sacs permit a unidirectional flow of air through the lungs. .... It is within 
these 'air capillaries' that the exchange of gases (oxygen and carbon ... (b) Some 
birds, such as ducks, have a relatively small neopulmonic region. .... is higher in 
oxygen content than, for example, air in the alveoli of humans and other 
mammals. [DOC] [TLE] Lungs - Your Amazing Body [PAR] Humans have two lungs, with the left being divided into two lobes and the ... of 
airways and 300 to 500 million alveoli, having a total surface area of about ... Air 
continues through these small airways until it finally reaches the tiny balloon-like 
air sacs ... Inside these alveoli, the exchange of oxygen and carbon dioxide 
occurs. [DOC] [TLE] THE RESPIRATORY SYSTEM - LeavingBio.net [PAR] Gas Exchange The Mechanism of Breathing Breathing Disorders Animation 
Links ... The main job of the respiratory system is to get oxygen into the body and 
get waste ... This helps to keep the air entering the nose from drying out the lungs 
and ... These tubes are lined with mucous

Question: Human lungs have millions of these tiny air sacs, where oxygen & carbon dioxide are exchanged
Answer: Alveoli