Final answer:
Each lung has an extensive network of airways that stretch to approximately 1,500 miles. The multiple alveoli within the lungs provide a total surface area of up to 90 square meters to facilitate gas exchange with the blood.
Step-by-step explanation:
The human respiratory tract features an extensive network of airways that allows for efficient gas exchange necessary for breathing. Within our bodies, the trachea and other pathways conduct air to an impressive 1,500 miles of airways, which lead to the lungs where the actual gas exchange takes place. Our lungs are comprised of millions of small, sac-like structures called alveoli, which greatly increase the surface area available for gas exchange. In fact, each lung contains about 300 million alveoli, giving a total surface area of up to 90 square meters, equivalent to the area of one side of a volleyball court.
This intricate respiratory network also includes the passage of air through the primary bronchi and subsequent smaller branches known as bronchioles, which terminate in alveolar sacs where the alveoli reside. This expansive surface area is critical for facilitating the diffusion of oxygen into the blood and the release of carbon dioxide from it, supporting the approximately 20,000 breaths we take each day.