2. Function of the Respiratory System To bring about the exchange of oxygen and carbon dioxide between the air, the blood, and the tissues.

4. Structures of the Respiratory System Nose/Mouth—warms, moisten, filters inhaled air Pharynx—food and air together here, passage to trachea Larynx (voice box)—location of vocal cords Trachea (wind pipe)—structure to keep airway open, lined with cilia to filter air Bronchi—(2 of them) one branch to each lung Lungs (that have bronchioles (smaller branches off bronchi) and alveoli (air sacs where gas exchange occurs) Diaphragm (muscle at base of rib cage that helps to fill lungs with air) Nose/Mouth—warms, moisten, filters inhaled air Pharynx—food and air together here, passage to trachea Larynx (voice box)—location of vocal cords Trachea (wind pipe)—structure to keep airway open, lined with cilia to filter air Bronchi—(2 of them) one branch to each lung Lungs (that have bronchioles (smaller branches off bronchi) and alveoli (air sacs where gas exchange occurs) Diaphragm (muscle at base of rib cage that helps to fill lungs with air)

5. Path of Air Path of Air to the Lungs --Nose or mouth  Pharynx  Larynx  Trachea  Bronchi Path of Air Inside the Lungs – Bronchioles  Alveoli Then air can exit in opposite direction Path of Air to the Lungs --Nose or mouth  Pharynx  Larynx  Trachea  Bronchi Path of Air Inside the Lungs – Bronchioles  Alveoli Then air can exit in opposite direction

6. Gas Exchange 150 million alveoli (air sacs) in each lung Oxygen dissolves in the moisture on the inner surface of the alveoli and then diffuses across the capillary wall into the blood stream Carbon dioxide in the blood moves from the blood to the alveoli and is then exhaled. 150 million alveoli (air sacs) in each lung Oxygen dissolves in the moisture on the inner surface of the alveoli and then diffuses across the capillary wall into the blood stream Carbon dioxide in the blood moves from the blood to the alveoli and is then exhaled.

7. Breathing Movement of air into and out of lungs No muscle connected to lungs Air pressure forces air into the lungs The diaphragm is a muscle at the bottom of the body cavity Movement of air into and out of lungs No muscle connected to lungs Air pressure forces air into the lungs The diaphragm is a muscle at the bottom of the body cavity

8. Inhaling The diaphragm moves down  the ribs move up and out  the chest cavity volume increases  creates a partial vacuum inside the body cavity  air is forced in

9. Exhaling Diaphragm moves down  the ribs move down and in  volume of chest decreases  internal pressure rises above air pressure outside of body  air is forced out

10. Disorders of Respiratory Sys Reduced air flow: asthma, emphysema, bronchitis Infections: pneumonia, tuberculosis, botulism Lung cancer Congestive heart failure Cystic fibrosis Reduced air flow: asthma, emphysema, bronchitis Infections: pneumonia, tuberculosis, botulism Lung cancer Congestive heart failure Cystic fibrosis

11. Four Respiration Processes Breathing (ventilation): air in to and out of lungs Cellular respiration: oxygen use to produce ATP, carbon dioxide as waste Breathing (ventilation): air in to and out of lungs Cellular respiration: oxygen use to produce ATP, carbon dioxide as waste