To prevent injecting an air bubble into your blood, which can kill you.
A sponge has minute holes , in which air is trapped , when we press it , the air is expelled out and we are able to compress it
Air is expelled from the alveoli, as well as the lungs in general, during exhalation when the diaphragm relaxes and rises up. This creates pressure on the thoracic cavity, and since there is more air pressure inside than outside, the air is exhaled to relieve the pressure.
The hot air expelled by congress as they lie about what they are not doing.
Here we go. When canned air is sprayed out, the air is expelled from the can. This removes heat from the can. Since the canned air is under pressure and there is more air in the can than whats surrounding the can, the inside temperature lessens as more air is expelled, removing more heat than the can can get from its ambient environment. The more you spray, the cooler the can can get and even ice up. It works just like a minerature air conditioner.
The greatest volume of air that can be expelled when a person performs rapid, forced expiration.
Tidal Volume
water is needed to keep the air in until the water is expelled out.
It is water droplets expelled into the air as the CO2 bubbles burst in their first rush.
O<~ the above shows a balloon traveling to the left as the air is being expelled.
It is physically impossible for feces from the lower intestine to go back up the digestive tract to the mouth. The only way for feces to get to the mouth would be for a person to put it there. Expelling would be called "spitting out."
Orally.