Trachea synthetic windpipes; however, a successful method for this method of transplant does not currently exist and development of such a method remains theoretically daunting. The word "trachea" is used to define a very different organ in invertebrates than in vertebrates. Insects have an open respiratory system made up of spiracles, tracheae, and tracheoles to transport metabolic gases to and from tissues. An adult's trachea has an inner diameter of about and a length of about 10 to 11 centimetres (4 in.). It begins at the bottom of the larynx, and ends at the carina, the point where the trachea branches
Effect of spaceflight on the human body of motion sickness for the first three days of travel due to the conflict between what the body expects and what the body actually perceives. Over time however the brain adapts and although these illusions can still occur, most astronauts begin to see "down" as where the feet are. People returning to Earth after extended weightless periods have to readjust to the force of gravity and may have problems standing up, focusing their gaze, walking and turning. This is just an initial problem, as they recover these abilities quickly. NASA jokingly measures SAS using the "Garn scale", named for United