First, the air enters the lungs through a process called Inhalation, then the Oxygen (O) is transferred to the heart via pulmonary veins that is in the heart, which is then delivered to the body systems via the bloodstream. The remaining Carbon Dioxide (CO2) exits by Exhalation.
The heart functions as the "Circulatory Pump". The lungs is a two sacs which inside it has happening.- Inside the lungs, the oxygen and carbon dioxide transfer places(oxygen is inserted in blood while carbon dioxide is expleted out the blood). They both help the body (such as muscles, tissues and body organs, even your brain!) send oxygen and nutrients to different places.