Pt.I
All living things needs some form of oxygen to live. In talking about a scuba diver, we are talking about a human, who uses their lungs to breathe, and did not develop the ability to breathe under water. Instead, when in a body of water, we tend to hold our breaths until an opportunity arises for us to exchange our carbon dioxide for oxygen.
Take into account the scuba gear. The scuba gear fits the user, and has a number of protection, including the suit counter-balancing any pressure applied by the deep, and the tank providing much needed oxygen to the user during delayed periods within the water.
Pt.II
<u>How does these two systems interact?</u>
Like as a human is breathing on land or even swimming, the human expels carbon dioxide, which forms into "air bubbles" that are then expelled into the water surrounding. The user then draws air from the pressurized air tank, and is able to breathe as such. This allows the user to stay underwater for much longer than just one breathe, and is able to travel farther inside the deep.
Inside this system, the Oxygen is first input into the oxygen tanks, which are then used by the diver. The diver would draw the oxygen from the tank (output), and he will then expel the used air into the surrounding water.
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