1. The Respiratory System

2. The system that provides oxygen for the body and allows carbon dioxide to leave the body This system works in close association with the circulatory system

3. Label the diagram: Nasal cavity Mouth Trachea Bronchi Bronchiole Lung Ciliated epithelial cells Alveoli

4. Structure of the Respiratory System Air enters through mouth and nasal cavity Travels through trachea Trachea separates into to bronchi (singular – bronchus) Bronchi split into bronchioles Alveoli are small sacs at the ends of the bronchioles These are the sites of gas exchange with the circulatory system

5. Structure of the Respiratory System Many of the epithelial cells that line the respiratory pathway are goblet cells (produce mucus). In addition, these cells also contain cilia Cilia help move mucus and filter out and materials that may enter the system (bacteria, dust, etc.) The trachea is supported by rings of cartilage This keeps the trachea open at all times, while still allowing flexibility (your ears are also made of cartilage)

6. Why doesn’t food get in my trachea? Because of the EPIGLOTTIS When you swallow, the epiglottis (a small flap) covers the opening of the trachea

7. Gas Exchange Oxygen and carbon dioxide need to be exchanged. This occurs between the alveoli of the respiratory system and the capillaries of the circulatory system An alveolus is a sac of air at the end of the respiratory system Each alveolus is surrounded by a capillary network

8. Gas Exchange Blood coming from the heart is deoxygenated (carrying CO 2 ) The CO 2 diffuses from the capillary to the alveolus O 2 diffuses from the alveolus to the capillary The CO 2 is EXHALED as waste The O 2 is then brought back to the heart, where it is pumped to all cells in the body.

9. Disorders and Diseases Tuberculosis Bronchitis Bronchial Asthma Carbon Monoxide Poisoning Lung Cancer Common Cold