1. Respiratory System Gas Transport by the Blood Xinping Yue xyue@lsuhsc.edu Department of Physiology LSUHSC-NO

3. At Standard Barometric Pressure Dry Atmospheric Gas (P) Inspired Gas (P I ) Alveolar Gas (P A ) Mixed Expired Gas (P E ) Po 2 159.0 mmHg149.0 mmHg104.0 mmHg120.0 mmHg Pco 2 0.3 mmHg 40.0 mmHg27.0 mmHg PN2PN2 600.6 mmHg564.0 mmHg569.0 mmHg566.0 mmHg PH2OPH2O 0 mmHg47.0 mmHg

4. O 2 = 150 torr CO 2 = 0 torr O 2 = 150 torr CO 2 = 0 torr O 2 = 100 torr CO 2 = 40 torr O 2 = 100 torr CO 2 = 40 torr O 2 = 100 torr CO 2 = 40 torr O 2 = 40 torr CO 2 = 45 torr O 2 = 40 torr CO 2 = 45 torr Gas Transport

5. Transport of O 2 by the blood  Physically dissolved At 37°C, 1 ml of plasma contains 0.00003 ml O 2 /mm Hg P O 2 Normal arterial blood contains 0.3 ml O 2 /100 ml  Chemically combined to hemoglobin 1 gram of hemoglobin can combine with 1.34 ml of O 2 when fully saturated A person with 15 g Hb/100 ml of blood can carry 20.1 ml O 2 /100 ml blood % Hb saturation = x 100% O 2 bound to Hb O 2 capacity of Hb

7. Hemoglobin, human, adult (heterotetramer, (αβ) 2 ) The protein's α and β subunits are in red and blue, and the iron-containing heme groups in green Heme b group

8. Oxyhemoglobin Dissociation Curve

9. Bohr effect

11. Hemoglobin saturation, % Partial pressure of oxygen, mm Hg 20 40 60 80 100 20406080100120140160 P 50 50%  Pco 2,  pH  temp,  BPG  Pco 2,  pH  temp,  BPG

15. Cyanosis Occurs when more than 5 grams of hemoglobin/100 ml of arterial blood are in the “deoxy” state Absence of cyanosis does not rule out hypoxemia (anemia) Presence of cyanosis does not always indicate hypoxemia (polycythemia)

16. Transport of CO 2 by the blood  Physically dissolved (5-10%) At 37°C, 1 ml of plasma contains 0.0006 ml CO 2 /mm Hg P CO 2 Normal arterial blood contains 2.4 ml CO 2 /100 ml  Carbamino compounds (5-10%)  Bicarbonate (80-90%) CO 2 + H 2 O H 2 CO 3 H + + HCO 3 Carbonic Anhydrase Carbonic Anhydrase - CO 2 (Gas phase) (Dissolved in the aqueous phase)

17. R - N + CO 2 R - N + H + HHHH HHHH H COO - H COO - Terminal amine group Carbamino compound Carbamino Compound

18. Carbon Dioxide Dissociation Curve Haldane effect

22. A Classification of the Causes of Hypoxia Increased FIo 2 helpful? Classification PAo2PAo2 P ao 2 C ao 2 C vo 2 P vo 2 Hypoxic hypoxia Low alveolar Po 2 Diffusion impairment Right to left shunts V/Q mismatch Anemic hypoxia CO poisoning Hypoperfusion hypoxia Histotoxic hypoxia Low Norm Low Norm Low Norm Low High Low High Yes No Yes No Possibly No