You can deactivate your account temporarily and choose to come back whenever you want. To deactivate your account: 1  Click the account menu at the top right of any Facebook page. 2  Select Settings. 3  Click Security in the left column. 4  Choose Deactivate your account then follow the steps to confirm.
In the alveoli Alveolus (also called air sac) is the capillary-rich sac in the lungs where the exchange of oxygen and carbon dioxide takes place by diffusion.
Gas Exchange in the Lungs. Gas exchange in the lungs takes place in the tiny air sacs called alveoli in the lungs. The process of inhalation must inflate the alveoli, but it can only do so because of the presence of a surfactant fluid that coats the alveoli and lowers the surface tension of their walls.