Your diaphragm moves downward, creating less pressure inside your lungs. Air rushes in. Your lungs then filter the air and extract the oxygen, which is sent through your brochial tubes to your blood vessels, which distrubutes the oxygen around your body.
The blood leaving the lungs is loaded with oxygen, while blood entering the lungs is about to get oxygen from the respiratory system.
Aspiration is the medical term meaning food or liquid entering the lungs.
carbon dioxide
The epiglottis, a flap of tissue in the throat, prevents food from entering the lungs during swallowing by covering the opening to the windpipe.
epiglottis
The blood entering from the lungs has a high oxygen content and the blood entering from the body is high in carbon dioxide.
the eustachian tube
epiglottis closed up to protect food from entering the lungs
backward movement of epiglotis
After entering your nose and mouth, air travels down your windpipe (trachea) and into your lungs.
You are preventing oxygen from getting to your lungs.
the eustachian tube