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
Respiratory Zone
Copyright © 2008 Pearson
Education, Inc., publishing
as Benjamin Cummings.
Figure 16.3 (3 of 3)
Anatomy of the Respiratory Zone
Copyright © 2008 Pearson
Education, Inc., publishing
as Benjamin Cummings.
Figure 16.5a
Copyright © 2007 Lippincott
Williams & Wilkins.
McArdle, Katch, and Katch: Exercise
Physiology: Energy, Nutrition, and Human
Performance, Sixth Edition
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
11
Chest Wall and Pleural Sac
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Education, Inc., publishing
as Benjamin Cummings.
Figure 16.7
Pulmonary Pressures
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Education, Inc., publishing
as Benjamin Cummings.
Figure 16.8a–b
19
20
21
22
23
Volume and Pressure Changes
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Education, Inc., publishing
as Benjamin Cummings.
Figure 16.13
Spirometry
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Education, Inc., publishing
as Benjamin Cummings.
Figure 16.15
26
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
Conducting
zone
(anatomical
dead space)
Fresh air
“Old air”
Alveolus
Expiration
(c)
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Education, Inc., publishing
as Benjamin Cummings.
Inspiration
(a)
CO2
O2
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 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
Copyright © 2008 Pearson
Education, Inc., publishing
as Benjamin Cummings.
Table 16.1
Definitions of Dead Space
Anatomic Dead Space
Physiologic Dead Space
Low Blood Flow
Copyright © 2006 by Elsevier, Inc.
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