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0:00
Hello, this is Henry Fessler.
I'm a Professor of Medicine at
Johns Hopkins University
School of Medicine and
Director of Education
in the division
of pulmonary and critical care.
The first lecture discussed
the static elastic properties
of the lung and chest wall,
and how these physiological
characteristics
result in some of the
specific named lung volumes.
This lecture will cover how we
measure clinically
important lung volumes in
the pulmonary function
laboratory and how we can
interpret and apply the
findings in patients.
0:28
In this lecture, I'll review
the definition of the
name of the lung volumes.
Then, I'll discuss in some
detail the principles of
measurement by three different
techniques, gas dilution,
the most commonly used method,
body plethysmography,
the most difficult-to-pronounce
method, and radiology.
Finally, I'll say
a few words about
the interpretation
of abnormalities.
0:49
To review from the basic
physiology lecture,
there are four named major
lung volumes of the lung:
tidal volume, residual volume,
expiratory reserve volume, and
inspiratory reserve volume.
There are also four
named capacities:
total lung capacity,
functional residual capacity,
vital capacity, and
inspiratory capacity.
1:12
Many of these volumes and
capacities can be measured
with a spirometer,
arguably the most
important piece of
pulmonary function
testing equipment.
Although modern equipment is
more compact and computerized,
this photo of a traditional
water-filled spirometer
more clearly illustrates
how it works.
The patient inhales in
and out of a mouthpiece.
This raises or lowers a
lightweight plastic bell,
while the excursions of the bell
are recorded in units of volume
against time on a rotating
drum called a kymograph.
