Lesson 4: Lung Capacity

Question 1

Lung Capacity

Answer 1

Under normal conditions, your regular breathing does not use up the full capacity of your lungs. As your body’s needs increase, such as when you exercise, the volume of air drawn in can also increase.

The volume of air can be
recorded on a spirogram using a devices known as a spirometer.

There are several different
volumes of air that are drawn in or pushed out by the lungs;

Tidal Volume

Inspiratory Reserve
Volume

Expiratory Reserve Volume

Residual Volume

Question 2

Tidal
Volume

Answer 2

Tidal Volume is the
volume of air inhaled and
exhaled in a normal
breathing movement

Question 3

Inspiratory
Reserve
Volume

Answer 3

Inspiratory Reserve
Volume is the additional
volume of air that can be
taken in, beyond a regular
or tidal inhalation.

Question 4

Expiratory
Reserve
Volume

Answer 4

Expiratory Reserve
Volume is the additional
volume of air that can be
forced out of the lungs,
beyond a regular or tidal
exhalation.

Question 5

Residual
Volume

Answer 5

Residual Volume is the
amount of gas that remains
in the lungs and the
passageways of the
respiratory system even after a full exhalation. This volume never leaves the respiratory system; if it did, the lungs and respiratory passageways would collapse.

Question 6

Lung Capacities

Answer 6

Vital Capacity is the total volume of gas that can be moved in or out of the
lungs. It can be calculated as tidal volume + inspiratory reserve volume +
expiratory reserve volume = vital capacity.

Inspiratory Capacity is the total volume of gas that can be moved into the lungs.

Functional Residual Capacity is the total volume of air that can be moved out of the lungs.

Total Lung Capacity is the maximum volume of air present in the lungs.