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.Continue Reading
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.Learn more about Organs
Gas exchange in the lungs allows oxygen to diffuse through the small air sacks or alveoli at the end of one's bronchial tubes into the blood, and it allows carbon dioxide to move from the blood into the alveoli to allow the individual to expel the waste. Fresh oxygen comes into the lungs when one inhales and is removed upon exhaling, according to WebMD.Full Answer >
Gaseous exchange takes place in the lungs' alveoli, which are tiny sacs found at the ends of the terminal bronchioles. The gases that are exchanged are oxygen and carbon dioxide.Full Answer >
The lung parenchyma constitutes a network of thin-walled alveoli, which facilitate pulmonary gas exchange, notes the United States National Library of Medicine. This matrix of tiny air sacs encompasses a vast internal surface area, which is essential for efficient exchange of oxygen and carbon dioxide.Full Answer >
Pulmonary edema is the medical term used to refer to the accumulation of fluid in the lungs, specifically in the alveoli or air sacs, according to Medical News Today. It affects gas exchange and makes breathing difficult. It is rarely fatal with prompt and adequate treatment.Full Answer >