AP BIOLOGY

Detailed explanation-1: -When you inhale (breathe in), air enters your lungs, and oxygen from that air moves to your blood. At the same time, carbon dioxide, a waste gas, moves from your blood to the lungs and is exhaled (breathed out). This process, called gas exchange, is essential to life.

Detailed explanation-2: -When you breathe out, or exhale, your diaphragm relaxes and moves up into your chest cavity. As the space in your chest cavity gets smaller, air rich in carbon dioxide is forced out of your lungs and windpipe, and then out your nose or mouth.

Detailed explanation-3: -Carbon dioxide (CO2) is a waste product of cellular metabolism. You get rid of it when you breathe out (exhale). This gas is transported in the opposite direction to oxygen: It passes from the bloodstream – across the lining of the air sacs – into the lungs and out into the open.

Detailed explanation-4: -Breathing means taking in air rich in oxygen and giving out air rich in carbon dioxide with the help of respiratory organs. The taking in of air rich in oxygen into the body is called inhalation and giving out of air rich in carbon dioxideis known as exhalation.

Detailed explanation-5: -When you breathe out, the “balloons” relax and air moves out of the lungs. Tiny blood vessels surround each of the 300 million alveoli in the lungs. Oxygen moves across the walls of the air sacs, is picked up by the blood and carried to the rest of the body.