Transcript Prezentace aplikace PowerPoint

Respiratory Physiology
- introduction
Daniel Hodyc
Department of Physiology
UK 2.LF
Respiratory Physiology
1. Pulmonary Ventilation
2. Mechanics of Breathing
3. Ventilation/perfusion ratio, regulation
4. Regulation of Breathing
Gas transport in lungs
1. Pulmonary ventilation
- transport of gases to alveoli
2. Pulmonary diffusion
factors determining gas transport across
the membrane
3. Perfusion
4. Ventilation/perfusion ratio
Pulmonary ventilation
1. Partial pressure
2. Lung volumes and capacities
3. Alveolar ventilation
4. Anatomical and functional death
space, effective ventilation
Partial pressure of the gas
- in determined by its concentration in the
mixture and by the overall pressure of the
gas mixture
PatmO2 = Patm * FO2
PatmO2 = 740 torr * 0,21
- in the liquid - partial pressure of the gas
component, which is balanced with the liquid
Lung volumes and capacities
tidal volume
expiratory reserve volume
residual volume
inspiratory reserve volume
Lung volumes and capacities
Spirometer - measurement of lung volumes
- measurement of the oxygen consumption
Measurement of residual volume and FRC
- helium equilibration method
C1 * V1
Uneven ventilation
C2 * (V1 + V2)
Inaccurate measurement
Measurement of functional residual capacity
- pletysmograph
Boyl´s law: P * V = const
P1* V1
P1* V1 = P1´* (V1 - dV)
P2* V2
P2* V2 = P2´* (V2 + dV)
V2 = FRC
Air composition in respiratory system
Alveolar ventilation
ventilation of anatomic dead space
02
C02
inspiration
expiration
Alveolar ventilation
Relationship between tidal volume,
frequency and effective ventilation
Minute
ventilation
ml/min
Tidal
volume
ml
Frekvency
c/s
Alveolar Ventilation
Ventilation Anat. dead
ml/min
space
ml/min
8000
250
32
3200
4800
40
8000
500
16
5600
2400
70
8000
1000
8
6800
1200
85
Why not to breathe with minimal frequency?
Work of breathing
Effective
ventilation
%
Measurement of anatomic dead space
Fowler´s
method
- insp - 100% 02
- exp - nitrogen
concentration
measurement
VD
Physiologic dead space
ventilated but not perfused alveoli
Bohr
equation
VD
=
VT
PaCO2 - PECO2
PaCO2
VT
ventilation of anatomic dead space
VA
ventilation of physiologic dead space
VAeff
PECO2
PACO2
PaCO2
Uneven ventilation
The worst ventilation - apical parts
Summary
- lung volumes measurable by spirometer
(VT,IRV,ERV)
- RV, FRC - measurable by He, plethysmograph
- anatomic dead space
- effective ventilation and respiratory frequency,
work of breathing
- physiologic dead space,
Thank you
for your
attention
Pictures and schemes – J.B.West - Respiratory Physiology, LWW
- Guyton, Hall - Textbook of Medical Physiology, 11th