Respiratory System

1. Respiratory System Ch 22

2. Respiration 4 PROCESSES • Breathing (Pulmonary Ventilation) • External Respiration • Internal Respiration • Cellular Respiration

3. Sinus Cavity • act as resonance chambers for speech • mucosa warms and moistens the incoming air • lightens facial bones

4. Pharynx • Connects nasal cavity and mouth to larynx and esophagus • 1)nasopharynx- air passage • Eustatian tube • Adenoids (pharyngeal) tonsils- mass of lymphoid tissue • traps and destroys pathogens • produces lymphocytes • helps fight infection • 2)oropharynx- serves as a common conduit for air and food • palatine and lingual tonsils • 3)laryngopharynx- accommodates both ingested food and air • located at junction where tracheae and esophagus splits • continuous with esophagus

5. Pharynx • Epiglottis- flexible elastic cartilage • attached to the wall of the pharynx near the base of the tongue • Larynx- voice box; thyroid cart. that attaches to hyoid bone superior and cricoid inferior • Provides open airway • Junction for food and air • Voice production

6. Pharynx Nasopharynx Oropharynx Laryngopharynx

8. Olfactory epithelium Olfactory tract Olfactory bulb Nasal conchae Route of inhaled air

9. Trachea 16 C-shaped rings of hyaline cartilage (thyroid +cricoid + tracheal cartilage's, includes epiglottis (elastic cart) make up larynx Function- hold trachea open Laryngitis- inflammation of the vocal cords resulting in inability to speak; due to voice overuse, very dry air, bacterial infection, and inhalation of irritating chemicals

10. The Trachea posterior esophagus hyaline cartilage ring lumen Mucus membrane submucosa adventitia anterior

11. Trachea

12. The Trachea

13. mucus cilia Epithelial Lining of the Trachea

14. Vocal Cords • True vocal cords are inferior to false vocal cords • Sound is produced when expelled air is passing through the larynx over the vocal cords

15. Lungs

16. Alveoli

17. Alveoli

18. Alveoli

19. Thoracic Cavity

20. Thoracic Cavity

21. Partial Pressure Gradients

22. Ventilation-Perfusion Coupling

23. Mechanics of Breathing • 2 muscles involved with breathing: • external intercostal muscles • diaphragm • Breathing controlled by: • phrenicnerve from medulla • pons

24. Mechanics of Breathing

25. Lung Ventilation 760 mm Hg 756 mm Hg Negative pressure draws air in Inspiration

26. Lung Ventilation Positive pressure forces air out 768 mm Hg Expiration

27. Lung Volumes Tidal Volume- 500 ml Vital Capacity- 4800 ml Residual Volume- 1200ml Total Lung Capacity- 4200-6000ml IRV- 3100 ml ERV- 1200ml Dead Space- 150 ml What factors affect lung volume?

29. What happens to TV, IRV, ERV, & VC during exercise? • TV  • IRV and ERV  • TLC and VC- doesn't change

30. Breathing Centers in the Brain

32. pons medulla oblongata Regulation of Breathing phrenic CO2 and H+ triggers breathing reflex in medulla, not presence of O2 vagus

34. Restrictive vs Obstructive Air Flow • Restrictive- more diff. to get air in to lungs • Loss of lung tissue • Decrease in lungs ability to expand • Decrease in ability to transfer O2 and CO2 in blood • Diseases: • Fibrosis, sarcoidosis, muscular disease, chest wall injury, pneumonia, lung cancer, pregnancy, obesity •  VC, TLC, RV, FRC

35. Restrictive vs Obstructive Air Flow • Obstructive- more diff. to get air out of lungs • Airway narrows • Increase in time it takes to empty lungs • Diseases: • Emphysema, chronic bronchitis, asthma  VC,  TLC, RV, FRC

36. Chronic Obstructive Pulmonary Diseases

37. COPD Chronic bronchitis- (obstructive) inhaled irritants lead to chronic excessive mucous production and inflammation and fibrosis of that mucosa;  the amt of air that can be inhaled; use bronco- dilators and inhalers Emphysema- (obstructive and restrictive) enlargement of alveoli; alveolar tissue is destroyed resulting in fewer and larger alveoli; inefficient air exchange; smoker's disease;  amt of air that can be exhaled Asthma- (obstructive disorder) cold, exercise, pollen and other allergens; from 1979-1989 the number of asthmatic deaths doubles

38. COPD Tuberculosis (TB)- (restrictive) infectious disease cause by bacterium Mycobacterium tuberculosis. Spread through air borne bacteria from infected person's cough. Total lung capacity declines Symptoms: fever night sweats, wt. loss, racking cough, and spitting up blood Polio- TLC declines (restrictive) Eliminated in U.S. and Western Hemisphere Still exists in Africa Lung cancer- promoted by free radicals and other carcinogens; very aggressive and metastasizes rapidly

39. Smoker’s lung Normal lung

40. Dalton's Law of Partial Pressure The total pressure of a gas exerted by a mixture of gas is the sum of the gases exerted independently. Air % partial pressure (mm Hg) N2 78.6 597 O2 21.0 159 CO2 0.04 0.3 H2O 0.46 3.7 Total 100 760 Partial pressure is directly related to its % in the total gas mixture. E.g., at 1 atm PO2 = 159 mm Hg

41. Henry's Law When a mixture of gas is in contact w/a liquid, each gas will dissolve in the liquid in proportion to its partial pressure. Gasses can go in and out of solution e.g., open soda, get CO2 bubbles (CO2 is under pressure)

42. Decompression Sickness It is caused when N2 enters the blood circulation and the tissues. When extra N2 leaves the tissues, large bubbles form. N2 bubbles can travel throughout the system and into the lungs and blood routes. Treatment: hyperbaric chamber

45. Hyperbaric Chamber

46. Erythrocytes Function- transport respiratory gases Lack mitochondria. Why?

47. Hemoglobin- quaternary structure 2  chains and 2  chains Hemoglobin Structure 1 RBC contains 250 million hemoglobin molecules

48. Uptake of Oxygen by Hemoglobin in the Lungs O2 binds to hemoglobin to form oxyhemoglobin High Concentration of O2 in Blood Plasma High pH of the Blood Plasma oxyhemoglobin O2

49. O2 pickup CO2 release

50. Unloading of Oxygen from Hemoglobin in the Tissues When O2is releaseddeoxyhemoglobin Low Concentration of O2 in Blood Plasma Lower pH of the Blood Plasma