ANT- Respiratory System Structure and Function Name ________________________ Date __________ Class __________ 1. Air enters the Nares or Nostrils 2. Air is then warmed and moistened while dust particles are filtered out in the Nasal Cavities. 3. Air passes through the Pharynx, the region behind the nasal cavity and mouth through which both food and air pass. 4. Next it travels through the Larynx which is made of cartilage, contains the vocal chords and functions as the voice box. 5. The Trachea is found below the larynx and is where air enters the chest cavity. 6. The trachea divides into two tubes, the Bronchi which carry the air to either the left or right lung. 7. The air passages get smaller as the Bronchi branch off into the bronchioles. 8. At the end of the bronchioles are found Alveoli, chamber-like bulges that have very thin walls- usually only one cell thick. 9. Alveoli are surrounded by capillaries (through which blood cells flow) and are the site of gas exchange. 10. The Diaphragm muscle separates the chest cavity and the abdominal cavity. When it contracts, O2 is pulled into the lungs and when it relaxes CO2 is released. 2. 9. 7. 3. 1. 4. 6. 5. 8. 7. 10.