The path followed by air as it passes through the lungs in mammals
Answer Details
When mammals breathe in, air enters through the nostrils and flows into the nasal cavity. The air is then filtered, warmed, and humidified by the mucous membranes and tiny hairs inside the nasal cavity. From there, the air travels down the pharynx, a tube that connects the nasal cavity to the larynx. The larynx is where the vocal cords are located and it also acts as a valve to prevent food and liquid from entering the lungs. After passing through the larynx, the air enters the trachea, which is also known as the windpipe. The trachea is a tube made of rings of cartilage that keeps it open. The trachea branches into two tubes called bronchi, one leading to the left lung and one to the right lung. Inside the lungs, the bronchi continue to divide into smaller and smaller tubes called bronchioles. These bronchioles eventually lead to tiny air sacs called alveoli, which are surrounded by tiny blood vessels called capillaries. It is at the alveoli where the exchange of gases occurs. Oxygen from the air diffuses through the walls of the alveoli and into the capillaries, where it binds to red blood cells and is transported throughout the body. At the same time, carbon dioxide from the body diffuses from the capillaries into the alveoli, where it is exhaled out of the body when we breathe out. Therefore, the path followed by air as it passes through the lungs in mammals is: nostrils → nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli.