Pulmonary Ventilation Dr. Imrana Ihsan
Copyright © 2007 Lippincott Williams & Wilkins. McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition
Copyright © 2007 Lippincott Williams & Wilkins. McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Respiratory Zone Figure 16.3 (3 of 3)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Anatomy of the Respiratory Zone Figure 16.5a
Copyright © 2007 Lippincott Williams & Wilkins. McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition
11 PULMONARY VENTILATION: MECHANISM – Pressure gradients are established by changes in the size of the thoracic cavity that are produced by contraction and relaxation of muscles (Figures 24-4 and 24-5) – Boyle’s law: the volume of gas varies inversely with pressure at a constant temperature – Inspiration: contraction of the diaphragm and external intercostals produces inspiration; as they contract, the thoracic cavity becomes larger (Figures 24-6 and 24-7) Expansion of the thorax results in decreased intrapleural pressure, leading to decreased alveolar pressure Air moves into the lungs when alveolar pressure drops below atmospheric pressure Compliance: ability of pulmonary tissues to stretch, thus making inspiration possible
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Chest Wall and Pleural Sac Figure 16.7
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Pulmonary Pressures Figure 16.8a–b
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Volume and Pressure Changes Figure 16.13
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Spirometry Figure 16.15
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Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Minute Ventilation Total volume of air entering and leaving respiratory system each minute – Minute ventilation = V T x RR – Normal respiration rate = 12 breaths/min – Normal V T = 500 mL – Normal minute ventilation = 500 mL x 12 breaths/min = 6000 mL/min
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Dead Space and Ventilation Figure Fresh air “Old air” Alveolus Conducting zone (anatomical dead space) ExpirationInspiration Exchange with blood CO 2 O2O2 (a) (b) (c)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Alveolar Ventilation – Volume of air reaching the gas exchange areas per minute – Alveolar ventilation = (V T x RR) – (DSV x RR) – Normal = 4200 mL/min (500 mL/br x 12 br/min) – (150 mL/br X 12 br/min)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Respiratory Rate and Ventilation Table 16.1
Anatomic Dead Space Low Blood Flow Physiologic Dead Space Definitions of Dead Space Copyright © 2006 by Elsevier, Inc.
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