What is the primary function of the lower respiratory system?

The lower respiratory system includes structures such as the trachea, bronchi, and lungs, where gas exchange occurs. Its primary role is to take oxygen from inhaled air and move it into the blood, while carbon dioxide leaves the blood to be exhaled. Therefore, “to extract oxygen from the air that the body breathes in” is correct; moving nutrients or blood is not the respiratory system’s primary function.

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