Pulmonary Ventilation Dr amna tahir Learning outcomes At

Learning outcomes At the end of this lecture you are able to get the

Copyright © 2007 Lippincott Williams & Wilkins. Mc. Ardle, Katch, and Katch: Exercise Physiology:

Respiratory Zone Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings. Figure

Anatomy of the Respiratory Zone Copyright © 2008 Pearson Education, Inc. , publishing as

PULMONARY VENTILATION: MECHANISM – Pressure gradients are established by changes in the size of

Chest Wall and Pleural Sac Copyright © 2008 Pearson Education, Inc. , publishing as

Pulmonary Pressures Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings. Figure

Volume and Pressure Changes Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

Spirometry Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings. Figure 16.

Minute Ventilation Total volume of air entering and leaving respiratory system each minute –

Dead Space and Ventilation Conducting zone (anatomical dead space) Fresh air “Old air” Alveolus

Alveolar Ventilation – Volume of air reaching the gas exchange areas per minute –

Respiratory Rate and Ventilation Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

Definitions of Dead Space Anatomic Dead Space Physiologic Dead Space Low Blood Flow Copyright

Slides: 34

Download presentation

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

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 12

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 m. L – Normal minute ventilation = • 500 m. L x 12 breaths/min = 6000 m. L/min Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings.

Dead Space and Ventilation Conducting zone (anatomical dead space) Fresh air “Old air” Alveolus Expiration (c) Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings. Inspiration (a) CO 2 Exchange with blood (b) Figure 16. 17

Alveolar Ventilation – Volume of air reaching the gas exchange areas per minute – Alveolar ventilation = (VT x RR) – (DSV x RR) – Normal = 4200 m. L/min (500 m. L/br x 12 br/min) – (150 m. L/br X 12 br/min) Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings.

Thank you