2. Maximum Expiration Maximum inspiration 6000 ml 2300 ml 1200 ml 0 ml Tidal volume 500 ml 2800 ml Expiratory reserve volume 1100 ml Residual volume 1200 ml Inspiratory reserve volume 3200 ml All muscles relaxed Vital capacity 4800 ml Total lung capacity 6000 ml Inspiratory capacity 3700 ml Functional residual capacity 2300 ml

3. *The Four “Main” Volumes*

4. Maximum Expiration Maximum inspiration 6000 ml 2300 ml 1200 ml 0 ml * Tidal volume = 500 ml * 2800 ml * Expiratory reserve volume 1100 ml * * Residual volume 1200 ml * * Inspiratory reserve volume 3200 ml * All muscles relaxed Dead space volume = 150 ml Alveolar volume = 350 ml Alveolar volume = up to 3550 ml for a “deep breath”

5. 1. Tidal volume – The volume of air moved in and out of the respiratory tract during “quiet” breathing. The average volume is 500 ml per breath and it is sometimes called a “resting breath.” Each breath is divided into two separate volumes: A. Alveolar volume – The volume of air that actually makes it into the alveoli. For a resting breath this is about 350 ml. Remember this is simply an additional 350 ml to what is already in the alveoli and this amount will continue to increase as the volume of inspiration increases up to 3550 ml for a “deep breath”. B. Dead space volume – The volume of air that does not make it to the alveoli with each breath, but is instead caught in the remainder of the respiratory tract from the nostrils to the bronchioles. The volume is about 150 ml and is a constant amount of air, regardless of the volume of inspiration or expiration.

6. 2. Inspiratory reserve volume – The volume of air that can be inspired beyond the tidal volume. The average volume is 3200 ml and represents the additional amount of air, beyond a resting breath, a person can take in if they want to take a “deep breath.” 3. Expiratory Reserve Volume – The volume of air that can be expired beyond “normal” or “passive” expiration. The maximum average volume that can be expired is 1100 ml and the movement of this air out of the lungs is controlled by the contraction of the internal intercostal & abdominal muscles. 4. Residual Volume – The volume of air that cannot be expired from the lungs without collapsing them. Therefore, this volume is held in the lungs at all times and could be considered the minimum inflation level of the lungs. The residual volume has an average of 1200 ml.

7. The Four “Main” Capacities

8. Maximum Expiration Maximum inspiration 6000 ml 2300 ml 1200 ml 0 ml 2800 ml Vital capacity 4800 ml Total lung capacity 6000 ml Inspiratory capacity 3700 ml Functional residual capacity 2300 ml All muscles relaxed

9. Inspiratory capacity – The total volume of air that can be inspired by contraction of the diaphragm and external intercostal muscles. It is the tidal volume + inspiratory reserve volume . The average volume is 3700 ml and represents the amount of air a person can take in by active inspiration . Functional Residual Capacity – The amount of air that is usually retained in the lungs while at rest. It is the residual volume plus the expiratory reserve volume and averages about 2300 ml.

10. Vital Capacity – The maximum amount of air that can be expired after maximum inspiration. It is the expiratory reserve volume plus the tidal volume plus the inspiratory reserve volume (or expiratory reserve volume plus the inspiratory capacity ). The average total is 4800 ml. Total Lung Capacity – The total amount of air that can be held in the lungs. It is the four main “volumes” added together or the functional residual capacity plus the inspiratory capacity . The average total is 6000 ml.

11. Maximum Expiration Maximum inspiration 6000 ml 2300 ml 1200 ml 0 ml Tidal volume 500 ml 2800 ml Expiratory reserve volume 1100 ml Residual volume 1200 ml Inspiratory reserve volume 3200 ml All muscles relaxed Vital capacity 4800 ml Total lung capacity 6000 ml Inspiratory capacity 3700 ml Functional residual capacity 2300 ml

12. A reminder of the muscle groups involved in breathing, but on the volumes & capacities chart.

13. Maximum Expiration Maximum inspiration 6000 ml 2300 ml 1200 ml 0 ml 2800 ml All muscles relaxed Contraction of: Diaphragm & External Intercostal “ Active” muscle “ Passive” air Relaxation of: Diaphragm & External Intercostal “ Passive” muscle “ Active” air Contraction of: Internal Intercostal & Abdominals “ Active” muscle “ Active” air Relaxation of: Internal Intercostal & Abdominals “ Passive” muscle “ Passive” air

14. Quiz Yourself!!

15. All muscles relaxed Maximum Expiration Maximum inspiration 6000 ml 2800 ml 2300 ml 0 ml 1200 ml Total Lung Capacity 6000 ml Vital Capacity 4800 ml Functional Residual Capacity 2300 ml Inspiratory Capacity 3700 ml Residual Volume 1200 ml Expiratory Reserve Volume 1100 ml Tidal Volume 500 ml Inspiratory Reserve Volume 3200 ml Dead Space Volume 150 ml Alveolar Volume = 350 to 3550ml