2. ECAP BIOL 61011 The Respiratory System Mrs. Riel

3. ECAP BIOL 61012 The Lung Main function is to transfer oxygen from the atmosphere to the blood - and carbon dioxide from the blood to the atmosphere

4. ECAP BIOL 61013 More Facts on the Lungs u The narrower portion of each lung is called the apex u The bases rest on the diaphragm u The left lung has two lobes u The right lung has three lobes

5. ECAP BIOL 61014

6. 5 Discuss the Anatomy of the Airway u The Upper Respiratory Tract includes the Nose, Nasal Cavity and the Pharynx u The Lower Respiratory Tract includes the Larynx, trachea, bronchi, bronchioles, alveolar ducts, and alveoli.

7. ECAP BIOL 61016 The Vocal Cords u Part of the mucous membrane of the larynx forms a pair of folds called the true vocal cords. u Vibration that results in speech

8. ECAP BIOL 61017 The Right Primary Bronchus u It is wider than the left bronchus u It is shorter than the left bronchus u It is straighter than the left bronchus u It is the more common site for an inhaled object to become lodged

9. ECAP BIOL 61018 Cilia u Hair like projections which acts like an escalator u The cilia of the nasal mucosa move contaminated mucus toward the pharynx for swallowing

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13. ECAP BIOL 610112

14. ECAP BIOL 610113 Define Simple Diffusion u Movement of molecules from an area of high concentration to an area of lower concentration u No energy involved

15. ECAP BIOL 610114 Explain gas exchange in the Alveolus u O 2 diffuses across the A/C membrane into the blood u CO 2 diffuses from the blood across the A/C membrane into the alveolus u Gas exchange occurs by simple diffusion

16. ECAP BIOL 610115 Events of Respiration Respiratory gas transport – transport of oxygen and carbon dioxide via the bloodstream Internal respiration – gas exchange between blood and tissue cells in systemic capillaries

17. ECAP BIOL 610116 Mechanics of Breathing (Pulmonary Ventilation) Completely mechanical process Depends on volume changes in the thoracic cavity Volume changes lead to pressure changes, which lead to the flow of gases to equalize pressure

18. ECAP BIOL 610117 Mechanics of Breathing (Pulmonary Ventilation) Two phases Inspiration – flow of air into lung Expiration – air leaving lung

19. ECAP BIOL 610118 Inspiration Diaphragm and intercostal muscles contract The size of the thoracic cavity increases External air is pulled into the lungs due to an increase in intrapulmonary volume

20. ECAP BIOL 610119 Inspiration

21. ECAP BIOL 610120Exhalation   Largely a passive process which depends on natural lung elasticity   As muscles relax, air is pushed out of the lungs   Forced expiration can occur mostly by contracting internal intercostal muscles to depress the rib cage

22. ECAP BIOL 610121 Exhalation

23. ECAP BIOL 610122 Pressure Differences in the Thoracic Cavity Normal pressure within the pleural space is always negative (intrapleural pressure) Differences in lung and pleural space pressures keep lungs from collapsing

24. ECAP BIOL 610123 Carbon Dioxide u CO2 is one of the most important stimuli leading to increased rate and depth of breathing

25. ECAP BIOL 610124 Respiratory Volumes and Capacities Normal breathing moves about 500 ml of air with each breath (tidal volume [TV]) Many factors that affect respiratory capacity A person’s size, sex, age, & physical condition.

26. ECAP BIOL 610125 Respiratory Volumes and Capacities Inspiratory reserve volume (IRV) Amount of air that can be taken in forcibly over the tidal volume Usually between 2100 and 3200 ml Expiratory reserve volume (ERV) Amount of air that can be forcibly exhaled Approximately 1200 ml

27. ECAP BIOL 610126 Respiratory Capacities Slide 13.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 13.9

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