2DO NOW:Label the lung with the following terms: trachea, bronchi, bronchiole, draw alveoli
3REMEMBERAir flows through nose or mouth and enters the pharynx (throat)From the throat, air enters the trachea (windpipe) -Food enters the esophagusThe trachea is the pipe that brings air to the lungs
4The trachea splits into 2 openings to the lungs called bronchi These split into many branches in the lung called the bronchiolesAt the end of each bronchiole is a structure called alveoli, or the air sacsFrom the alveoli, Oxygen can diffuse into the blood.Carbon dioxide can diffuse from the blood to the alveoli to be exhaled.
5How does breathing work? What happens to your chest when you inhale?What happens to your chest when you exhale?
6The chest cavity is the area surrounded by the ribs. The bottom of the chest cavity is closed off by the diaphragm
8The diaphragm is a muscle that contracts and relaxes What happens to the size of the chest cavity when you breathe in?What happens to the size of the chest cavity when you breathe out?
9Do you think that breathing is caused when the diaphragm or contracts or relaxes?
10Inhalation happens when the diaphragm contracts Inhalation happens when the diaphragm contracts. This increases the size of the chest cavity.The increase in the size of the chest cavity causes a change in pressure, which naturally causes air to rush into the lungs.
11Exhalation happens when the diaphragm relaxes Exhalation happens when the diaphragm relaxes. This decreases the size of the chest cavity.The decrease in the size of the chest cavity causes a change in pressure, which naturally causes air to rush out of the lungs.