WASHINGTON, Sept. 6, 2022 – Alveoli are the basic functional units of the human respiratory system, acting as tiny air sacs that exchange gases. Air inhaled through the mouth and nose flows into the ...

Breathing intakes oxygen and expels carbon dioxide, and this gas exchange takes place in the alveoli in the lungs. Alveoli contain type 1 alveolar epithelial cells (AT1), which are involved in the ...

Researchers have identified a lung stem cell that repairs the organ's gas exchange compartment. They isolated and characterized these progenitor cells from mouse and human lungs and demonstrated they ...

Part of Biology (Single Science) Cells, organ systems and ecosystems The air that enters the nasal cavity flows down the trachea. The trachea has a number of adaptations: cartilage rings in the walls ...

You have millions of air sacs (alveoli) in your lungs. These air sacs move oxygen into your blood. Alveolar walls contain surfactant. This is a substance made of fats, proteins, and other substances.