1. 30.1 Respiratory and Circulatory Functions The respiratory and circulatory systems bring oxygen and nutrients to the cells.

2. 30.1 Respiratory and Circulatory Functions The respiratory system is where gas exchange occurs. –picks up oxygen from inhaled air –expels carbon dioxide and water nose sinus mouth epiglottis trachea lungs

3. 30.1 Respiratory and Circulatory Functions Breathing in driven by the diaphragm and muscles of the rib cage. Air flows from areas of high pressure to low pressure. Air inhaled. Muscles contract and rib cage expands. Diaphragm flattens and moves downward. Air exhaled. Muscles and rib cage relax. Diaphragm relaxes and rises.

4. 30.1 Respiratory and Circulatory Functions Path of Air (Hair filters dust) (Drives breathing) (Suspended in chest cavity bounded by ribs) Alveoli (Tiny air sacs surrounded by capillaries) (small tubes) (long, straight tube in chest cavity) (Muscular tube) (voice box with epiglottis (flap))

5. 30.1 Respiratory and Circulatory Functions

6. Oxygen and carbon dioxide are carried by the blood to and from the alveoli. –oxygen diffuses from alveoli into capillary –oxygen binds to hemoglobin in red blood cells –carbon dioxide diffuses from capillary into alveoli ALVEOLI GAS EXCHANGES capillaries alveolus capillary co 2 o2o2 Co 2 diffuses into alveolus. O 2 diffuses into blood.

7. 30.1 Respiratory and Circulatory Functions Lung diseases reduce airflow and oxygen absorption. –Asthma constricts airways. –Emphysema destroys alveoli. –Cystic fibrosis produces sticky mucus.