This document discusses lung volumes and capacities. It defines four lung volumes: tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. It also defines four lung capacities that are combinations of the volumes: inspiratory capacity, vital capacity, functional residual capacity, and total lung capacity. It provides the normal values for each volume and capacity. Lung function tests measure these volumes and capacities to evaluate lung health and detect respiratory diseases. Spirometry uses a device called a spirometer to measure the volumes expired and inspired.

1. Respiratory system
Lung volumes and capacities
Mr N.JEGAN
Associate Professor
K.M.COLLEGE OF PHARMACY.
MADURAI.

2. Respiratory system

3. Lungs volume-Introduction
 Lung volumes are also known as respiratory volumes.
 In normal quiet breathing there are about 15
respiratory cycles per minute.

4. Importance to measure the lungs volume
Lung function tests are based on the
measurement of volume of air breathed in and out in
quiet breathing and forced breathing.
These volumes tend to vary, depending on the
depth of respiration, gender, age, body
composition and in certain respiratory diseases.
It used to find the person have any lungs related
diseases.

5. Lung volumes
Lung volumes are the volumes of air breathed by an
individual.
Lung volumes are of four types:
1. Tidal volume
2. Inspiratory reserve volume
3. Expiratory reserve volume
4. Residual volume

6. Tidal volume(TV)
This is the amount of air which passes into
and out of the lungs in a single normal quiet
respiration.
Normal value-500 ml

7. Inspiratory reserve volume(IRV)
It is an additional volume of air that can be
inspired forcefully after the end of normal
inspiration.
Normal value-3300 ml

8. Expiratory reserve volume(ERV)
It is the additional volume of air that can be
expired out forcefully, after normal expiration.
Normal value-1000 ml

9. Residual volume(RV)
It is the volume of air remaining in lungs even after
forced expiration.
Normally, lungs cannot be emptied completely even
by forceful expiration.
Some quantity of air always remains in the lungs
even after the forced expiration.
Normal value-1200 ml

10. LUNG CAPACITIES
Lung capacities are the combination of two or
more lung volumes.
Lung capacities are of four types:
1. Inspiratory capacity
2. Vital capacity
3. Functional residual capacity
4. Total lung capacity.

12. Inspiratory capacity(IC)
It is the maximum volume of air that is inspired
after normal expiration (end expiratory position).
It includes tidal volume and inspiratory reserve
volume
IC = TV + IRV
IC= 500 + 3,300 = 3,800 ml
Normal value-3800 ml

13. Vital capacity(VC)
It is the maximum volume of air that can be
expelled out forcefully after a deep (maximal)
inspiration.
VC includes inspiratory reserve volume, tidal
volume and expiratory reserve volume.
VC = IRV + TV + ERV
VC= 3,300 + 500 + 1,000 = 4,800 ml
Normal value-4800 ml

14. Functional residual capacity(FRC)
It is the volume of air remaining in lungs after
normal expiration (after normal tidal expiration).
Functional residual capacity includes expiratory
reserve volume and residual volume.
FRC = ERV + RV
FRC= 1,000 + 1,200 = 2,200 ml
Normal value-4800 ml

15. Total lung capacity(TLC)
It is the volume of air present in lungs
after a deep (maximal) inspiration.
It includes all the volumes.
TLC = IRV + TV + ERV + RV
TLC= 3,300 + 500 + 1,000 + 1,200 = 6,000 ml
Normal value- 6000 ml

16. Lungs capacities- Diagram

18. How to measure Lungs volume
Apparatus name-The Spirometer
A spirometer is an apparatus for measuring the
volume of air inspired and expired by the lungs.
you sit and breathe into a small machine called
a spirometer. This medical device records the amount
of air you breathe in and out and the speed of your
breath.

19. Spirometer

21. Next Topic
Artificial respiration,
and resuscitation methods.