Question

7. In your own words provide a one sentence definition/example of the following:

1. Vital capacity

2. Residual volume

3. Tidal volume

4. Total lung capacity

5. Functional residual capacity

6. Expiratory reserve volume

Answer 1

1. Vital capacity- it is the maximum amount of the air that a person can expel out  from his lungs after he inhales to his maximum.

it is usually 60-70ml per kg. vital capacity of normal adults is between 3 to 5 liters a day.

2. Residual volume- it is the amount of the air that is left out in the lungs even after fully exhaling.

normla range is 1 - 1.2 liters (normal adults, but varies with age, gender, race, height, weight, physical activity levels.)

3. Tidal volume- it is the measure of the amount of air a person inhales during normal breathing.

example- the amount of air you breathe in as you sit and read this answer. or its the amount of the air a person breathes when he is in a relaxed state (away from physical activity or any other form of stress.)

it is 500ml per inspiration on a general basis. (may vary based on population factors like age, gender, etc)

4. Total lung capacity- it is the maximum amount if air the lungs can hold.

it is the sum of all the lung volumes together. it is usually 4-6 liters.

5. Functional residual capacity- it is amount of air that is left in the lungs after normal expiration.

example- as we breathe out in in normal conditions (when we are not concentrating on breathing), the left out air in the lungs after we breathe out is called this.

it is around 2.5 liters in average sized umans or 35ml/kg.

6. Expiratory reserve volume- the amount of air we can expel by force after expiring normally.

example- after we breather in normally (tidal volume), we expire normally, then if we try to exhale more air out by force, this air is called expiratory reserve volume.

it is the amount of air we can force out after a normal breathe.