Do you know how your body gets oxygen from the air and removes carbon dioxide from your body? Right! It’s because of the respiratory system. Do you know how it works? The following explanation is written to help you understand the process clearly. The first phase of respiration is breathing in or inhalation. This process brings air from outside the body into the lungs. From the lungs, the oxygen moves through blood vessels to the heart which then pumps the oxygen-rich blood to all parts of the body. Oxygen then moves from the blood-stream into the cells, which completes the first phase of respiration. In the cells, oxygen is used in a separate energy-producing process which produces carbon dioxide as a byproduct. The second phase of respiration begins when the carbon dioxide moves from the cells to the bloodstream which carries carbon dioxide to the heart. Then, it pumps the carbon dioxide-laden blood to the lungs. In the lungs, breathing out or exhalation removes carbon dioxide from the body, thus completing the respiration cycle. From the lungs, the oxygen moves through blood vessels to the heart which then pumps the oxygen-rich blood to all parts of the body. The underlined conjunction can be replaced by….

Question

Do you know how your body gets oxygen from the air and removes carbon dioxide from your body? Right! It’s because of the respiratory system. Do you know how it works? The following explanation is written to help you understand the process clearly.

The first phase of respiration is breathing in or inhalation. This process brings air from outside the body into the lungs. From the lungs, the oxygen moves through blood vessels to the heart which then pumps the oxygen-rich blood to all parts of the body. Oxygen then moves from the blood-stream into the cells, which completes the first phase of respiration. In the cells, oxygen is used in a separate energy-producing process which produces carbon dioxide as a byproduct.

The second phase of respiration begins when the carbon dioxide moves from the cells to the bloodstream which carries carbon dioxide to the heart. Then, it pumps the carbon dioxide-laden blood to the lungs. In the lungs, breathing out or exhalation removes carbon dioxide from the body, thus completing the respiration cycle.

From the lungs, the oxygen moves through blood vessels to the heart which then pumps the oxygen-rich blood to all parts of the body.

The underlined conjunction can be replaced by….