Answer:The path that air takes from outside the body to the site of gas exchange can be described as follows:
1. Nose and Mouth: The air first enters the body through the nose or mouth.
2. Pharynx: The air then passes through the pharynx, which is the region at the back of the throat that serves as a common pathway for air and food.
3. Larynx: The air then passes through the larynx, which is commonly known as the voice box. The larynx contains the vocal cords and helps to produce sound.
4. Trachea: After passing through the larynx, the air enters the trachea, also known as the windpipe. The trachea is a tube made up of cartilage rings and lined with cilia, which help to filter and remove debris from the air.
5. Bronchi: The trachea divides into two bronchi, one for each lung.
6. Bronchioles: The bronchi then divide into smaller and smaller tubes called bronchioles.
7. Alveoli: The bronchioles terminate in small sacs called alveoli, which are the site of gas exchange in the lungs. Oxygen from the air diffuses across the walls of the alveoli and into the bloodstream, while carbon dioxide from the bloodstream diffuses into the alveoli to be exhaled.
Overall, the air passes through the nose/mouth, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli on its way to the site of gas exchange in the lungs.