1. Lungs and Respiratory system How do we get oxygen into the body?

2. Why do we need oxygen? Aerobic cells need oxygen to make energy (remember the yeast lab?)

3. Human Respiratory system Path of oxygen: Mouth/nose  pharynx  larynx  trachea  bronchi  lung Lungs have these parts: Bronchi  bronchioles  alveoli

4. Nose Function: prevent dust from getting into the lungs. Structures: Hair traps dust Mucus traps dust

5. Pharynx (again!) Function: prevent food getting into the lungs Structure: epiglottis, flap, closes when you swallow

6. Larynx Function: speaking Structure: contains the vocal cords

7. trachea Function: passage of air Structure: surrounded by cartilage

8. Bronchi Function: passage of air Two tubes that split from the trachea

9. Bronchioles Function: passage of air Structure: separates into smaller branches

10. alveoli Function: site of gas exchange Structure: very thin walls, surrounded with capillaries. Gas is carried in the blood by hemoglobin in RBC’s

11. Breathing The diaphragm is the muscle responsible for breathing When it contracts it expands the chest cavity. Negative pressure pulls air into the lungs http://www.youtube.com/watch?v= hp-gCvW8PRY

12. Breathing Breathing is controlled not by how much oxygen you have but by much CO 2 is in your blood. What can you do to hold your breath longer?

13. Smoking and lung cancer?