Pulmonary Ventilation Dr amna tahir
Learning outcomes At the end of this lecture you are able to get the idea of Pulmonary ventilation introduction of different pressure that normally involved \changed in normal respiration Muscles and movements related to respiration Alveolar ventilation DEAD SPACE, its types ,advantages and disadvantages
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
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 © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
Copyright © 2007 Lippincott Williams & Wilkins. McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition
PULMONARY VENTILATION: MECHANISM 1/18/2019 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
Chest Wall and Pleural Sac Figure 16.7 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
Pulmonary Pressures Figure 16.8a–b Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
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Volume and Pressure Changes Figure 16.13 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
Spirometry Figure 16.15 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
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Minute Ventilation Total volume of air entering and leaving respiratory system each minute Minute ventilation = VT x RR Normal respiration rate = 12 breaths/min Normal VT = 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 Fresh air “Old air” Alveolus Conducting zone (anatomical dead space) Expiration Inspiration Exchange with blood CO2 O2 (a) (b) (c) Figure 16.17 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
Alveolar Ventilation Volume of air reaching the gas exchange areas per minute Alveolar ventilation = (VT 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 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.
Definitions of Dead Space Anatomic Dead Space Physiologic Dead Space Low Blood Flow Copyright © 2006 by Elsevier, Inc.
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