When Abby Ellstrom and her friends at East High School in Denver crave classic chicken nuggets for lunch, the sophomores swipe the Uber icon on one of their smartphones and ride the nine blocks to Chick-fil-A.When they are done, they click Uber again for pickupâand make it back in time for their next class.y. When Abby Ellstrom and her friends at East High School in Denver crave classic chicken nuggets for lunch, the sophomores swipe the Uber icon on one of their smartphones and ride the nine blocks to Chick-fil-A. When they are done, they click Uber again for pickupâand make it back in time for their next class.
Trachea and Bronchi. The respiratory tree (figure 7-4) is the set of tubular structures which carry the air from the larynx to the alveoli of the lungs. Looking at a person UPSIDE DOWN, the trachea is the trunk of the tree and the bronchi are the branches. These tubular parts are held open (made patent) by rings of cartilage. Their lining is ciliated to remove mucus and other materials that get into the passageway.
As the bronchial tubes pass through the lungs, they divide into smaller air passages called bronchioles. The bronchioles end in tiny balloon-like air sacs called alveoli. Your body has over 300 million alveoli. The alveoli are surrounded by a mesh of tiny blood vessels called capillaries. Here, oxygen from the inhaled air passes through the alveoli walls and into the blood. After absorbing oxygen, the blood leaves the lungs and is carried to your heart. Your heart then pumps it through your body to provide oxygen to the cells of your tissues and organs.