Carbon dioxide diffuses out of the tissues and into the blood, where it is dissolved in the plasma. While some of the carbon dioxide remains dissolved in the plasma, most carbon dioxide diffuses into our red blood cells.
A screencast is a digital movie in which the setting is partly or wholly a computer screen, and in which audio narration describes the on-screen action. It's not a new idea.
A podcast, or generically netcast, is an episodic series of digital audio or video files which a user can download and listen to. It is often available for subscription, so that new episodes are automatically downloaded via web syndication to the user's own local computer, mobile application, or portable media player. It is distinct from Internet radio, which involves streaming rather than downloading. The word was originally suggested by Ben Hammersley as a portmanteau of iPod and broadcast