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1. Lecture:
“Pulmonary Ventilation
Spirography”
Vinnitsia-2019

2. Functions of lungs
Stages of respiration:
1.Pulmonary ventilation
2. Gases exchange in lungs
3. Transport of gases by blood
4. Gases exchange in tissues
5. Intracellular breathing

3. Respiration
Pulmonary ventilation. Factors, necessary
for it:
1. Hermeticity of the thorax and changing of its
volume due to respiratory muscles;
2. Negative intrapleural pressure;
3. Elasticity of the lungs;
4. Free connection of the air with the alveoli

5. Respiratory muscles
 Muscles of inspiration:
Diaphragm. (C3-C5); external intercostal
muscles and internal intercartilaginous
muscles.
Accessory inspiratory muscles are used during
exersises.
 Muscles of expiration: Passive expiration due to
relaxation of inspiratory muscles and elasticity
of lungs and chest (in rest).
Internal intercostal muscles, abdominal muscles

6. Intrapleural Pressure

7. Intrapleural Cavity.
Intrapleural pressure (IPP)
 Max. Expiration: IPP -1,5 (758,5) mmHg
 Pause (quite expiration): IPP -3 (757) mmHg
 Inspiration (quite): IPP -6;-9 (751-754) mmHg
 Max inspiration: IPP -10;-30 (750-730) mmHg
Pneumothorax: IPP=0 (760 mmHg) atmospheric
1-side, 2-side; open, closed; valvular

9. Pneumothorax

10. Elasticity of lungs. Surfactant
 Elastic tension of lungs:
1. Surface tension of liquid molecules inside of
alveoli (70%)
2. Elastic fibres of alveoli tension (30%)
3. Tone of small bronchi and bronchioles
Sufractant reduces surface tension. Includes
lipids and proteins (dipalmityl phosphatidyl
choline).
Functions of surfactant.
Control of surfactant synthesys.

11. Functions of surfactant.
Control of surfactant synthesys
 It provides stable shape of alveoli.
 Defense function. Cleaning of lungs.
 Newproduced surfactant increases O2
diffusion.
 Stimulate: parasympathetic n.s., deep
inspiration, food, including plant oils.
 Inhibits: sympathetic n.s., stress, nicotine,
acetone, washing powders (detergents).

12. Biomechanic of inspiration and
expiration
 ET + IPP = IAP (during pause)
 ET + IPP < IAP (during inspiration)
 ET + IPP > IAP (during expiration)
 Donders’ model
Passive role of lungs in pulmonary ventilation

13. Lung volumes. Spirometry

14. Lung volumes

15. Lung volumes
 Tidal volume (TV) 0,5 l; quite breathing
 Inspiratory reserve volume (IRV) 2,5-3 l max.
vol., can be inspired after quite inspiration
 Expiratory reserve volume (ERV) 1-1,5 l max.
vol., can be expired after quite expiration
 Vital capacity of lungs (VCL) 3,5-5 l for men
and 3-4 l for women; VCLm=height (cm)x25
VCL = TV+IRV+ERV; VCLw=height (cm)x20
 Residul volume (RV) can not be expired (1 l)
 Total capacity of lungs VCL+RV

16. Dynamic indexes of pulmonary
ventilation
 Minute pulmonary ventilation
 (MPV) = TV*breath. rate/min; 0,5*16=8 l/min
 Minute Alveolar ventilation (MAV)
 MAV= (TV-DS) *breath.rate/min
 Dead space air conduct ways (150ml)
 Coefficient of pulmonary ventilation:
CPV = (TV-DS):FRC; FRC=RV+ERV
CPV= (500-150):2500= 1/7 or 14% part of air

17. Dead space 150 ml

18. Residual volume determination

19. Thank you for attention!