1. Lungs By Amy Wen and Abby Nash

2. Background • In the respiratory system • Located above the diaphragm in the middle of the chest • Each lung is between 10 and 14 inches long • Two lungs in each body • Long and boat-shaped

3. Parts of Lung • Bronchi • Bronchioles • Alveoli • Membranes • Parietal Pleural • Visceral Pleural

4. Function • Transportation of oxygen from the air to the bloodstream • Transportation of carbon dioxide from the bloodstream into the air

5. Why is breathing necessary? • Cellular respiration • Requires oxygen • Produces carbon dioxide • Effect of exercise • Increases rate of respiration

6. Travel of Air to Lungs • Breathing controlled in brain stem and cerebral cortex • medulla oblongata • Chemoreceptors • Impulses

7. Travel of Air to Lungs Cont. • Impulses: rest vs. exercise • external intercostals • Diaphragm shape • parachute • Role of pressure • Alveoli impulses

8. Gas Exchange • Pathway of air • Nasal/oral cavities -> pharynx -> larynx -> trachea -> bronchi -> bronchioles -> alveoli • Exchange occurs between alveoli and surrounding capillaries

9. Gas Exchange Cont. • Diffusion • Requires concentration gradient • Efficient because • Surface area • Distance

10. Carbon Dioxide in the Blood • Bicarbonate ions • CO2 + H2O <--> H2CO3 <--> HCO3-+ H+ • Helps with diffusion (partial pressure) • Affect on pH of blood • Chemoreceptors

11. Lung Illnesses • Acute Mountain Sickness • Chronic Obstructive Pulmonary Disease • Emphysema • Pneumonia • Sleep Apnea

12. Acute Mountain Sickness • Symptoms • Caused by lower air pressure at high altitudes • Hard to diagnose if mild • Acclimatization is best treatment • Deadly

13. COPD & Emphysema • Chronic obstructive pulmonary disease includes emphysema • Progressive decrease in air flow and gas exchange • Overexposure to irritants • Destruction of alveoli walls

14. COPD & Emphysema Cont. • Spirometry test, chest x-ray, arterial blood gas test • No cure • Lifestyle changes can slow progress • Surgery, medication

15. Pneumonia • Inflammation, thick fluid in alveoli and bronchioles • Bacteria, viruses, or fungi • Fever, fatigue, coughing • Chest x-rays, blood tests • Treatment varies

16. Asthma • Bronchi and bronchioles sensitive to irritants • Smooth muscle around bronchioles contract and spasm • Wheezing, coughing, worse at night • Physical exam, spirometry test • Medication, avoid triggers

17. Sleep Apnea • Multiple pauses in breathing during sleep over 10 sec long • Obstructive and central type • Deep to light sleep • Hard to diagnose • Surgery, breathing devices

18. Interesting Details • Surfactant is essential • Surface tension of water • Alveoli would collapse without it • Lungs structured to trap and dispose of debris and microbes • Mucus and cilia

19. Thanks for listening!