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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.
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Respiratory Physiology- introduction Daniel Hodyc Department of Physiology UK 2.LF
Respiratory Physiology 1. Pulmonary Ventilation2. Mechanics of Breathing3. Ventilation/perfusion ratio, regulation4. Regulation of Breathing
Gas transport in lungs 1. Pulmonary ventilation - transport of gases to alveoli2. Pulmonary diffusionfactors determining gas transport across the membrane3. Perfusion4. Ventilation/perfusion ratio
Pulmonary ventilation 1. Partial pressure2. Lung volumes and capacities3. Alveolar ventilation4. 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
tidal volume expiratory reserve volume residual volume inspiratory reserve volume Lung volumes and capacities
Lung volumes and capacities Spirometer - measurement of lung volumes - measurement of the oxygen consumption
Uneven ventilation Inaccurate measurement Measurement of residual volume and FRC - helium equilibration method C1 * V1 C2 * (V1 + V2)
Measurement of functional residual capacity - pletysmograph Boyl´s law: P * V = const P1* V1 = P1´* (V1 - dV) P2* V2 = P2´* (V2+ dV) V2 = FRC P1* V1 P2* V2
Alveolar ventilation ventilation of anatomic dead space 02 C02 inspiration expiration
Relationship between tidal volume, frequency and effective ventilation Why not to breathe with minimal frequency? Work of breathing
Measurement of anatomic dead space Fowler´s method - insp - 100% 02 - exp - nitrogen concentration measurement VD
Physiologic dead space ventilated but not perfused alveoli VD PaCO2 - PECO2 Bohr equation = PaCO2 VT 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, workof 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