Copyright © 2006 by Elsevier, Inc. Uptake of Oxygen in Lungs Alveolar Diffusing capacity time in capillary (sec) P O2 in blood Normal 1/4 Normal 1/8 Normal
Copyright © 2006 by Elsevier, Inc. Uptake of Oxygen in Lungs with Low Alveolar Po 2 Alveolar Diffusing capacity time in capillary (sec) Po2 in blood Normal 1/4 Normal 1/8 Normal
Copyright © 2006 by Elsevier, Inc. Uptake During Exercise Increased cardiac output Decreased transit time Increased diffusing capacity –Opening up of additional capillaries –Better ventilation/perfusion match Equilibration even with shorter time
Copyright © 2006 by Elsevier, Inc. Oxygen Transport Percent Saturation (no units) HbO 2 (Hb+HbO 2 ) Content (ml O 2 /100 ml blood) absolute quantity of oxygen in blood
Copyright © 2006 by Elsevier, Inc. Dissolved oxygen –Solubility ml O 2 /100 ml blood/mmHg –Normal blood 0.3 ml O 2 / 100 ml blood at 100mmHg –Normal oxygen consumption ~250 ml O 2 /min –Would require 83 L/min blood flow Hemoglobin –97% transported by HBO 2 (oxyhemoglobin) O 2 + HB HBO 2 Transport of Oxygen in Blood
Copyright © 2006 by Elsevier, Inc. Hemoglobin –1.34 ml O 2 /gm Hb –Normal 15 gm Hb/100 ml blood 20 ml O 2 /100 ml blood –Anemic 10 gm Hb/100 ml blood 13 ml O 2 /100 ml blood Transport of Oxygen in Blood
Copyright © 2006 by Elsevier, Inc. Hemoglobin Dissociation Curve Lungs Tissue Content PO 2 Per cent Saturation
Copyright © 2006 by Elsevier, Inc. Right Shift of Dissociation Curve PO 2 Per cent Saturation pH PCO 2 Temp 2-3 DPG Normal Shift to right
Copyright © 2006 by Elsevier, Inc. Left Shift of Dissociation Curve Per cent Saturation pH PCO 2 Temp 2-3 DPG Normal Shift to left PO 2
Copyright © 2006 by Elsevier, Inc. The Oxygen-Hemoglobin Saturation Curve
Copyright © 2006 by Elsevier, Inc. The Effect of pH and Temperature on Hemoglobin Saturation
Copyright © 2006 by Elsevier, Inc. A Functional Comparison of Fetal and Adult Hemoglobin
Copyright © 2006 by Elsevier, Inc. Dissociation Curve Values to remember P O 2 (mmHg)Saturation (%)Content (ml/dl) Remember this is for a person with 15 gm/dl hemoglobin
Copyright © 2006 by Elsevier, Inc. Dissociation Curve hemoglobin myoglobin PO 2 Per cent Saturation
Copyright © 2006 by Elsevier, Inc. Calculations Calculate % saturation - Patient has Hb of 10 gm/dl - Venous oxygen content is 6.5 ml O 2 /dl Calculate oxygen content - Patient has saturation of 60% - Patient has Hb of 15 gm/dl
Copyright © 2006 by Elsevier, Inc. Calculations Calculate % saturation - 10 gm/dl * 1.34 ml O 2 /gm Hb= 13.4 ml O 2 /dl - This is max oxygen carrying capacity - (6.5 ml O 2 /dl) / (13.4 ml O 2 /dl) = ~50% Calculate oxygen content - 15 gm/dl * 1.34 ml O 2 /dl = 20 ml O 2 /dl - This is max oxygen carrying capacity - 20 ml O 2 /dl * 60% saturation = 12 ml O 2 /dl
Copyright © 2006 by Elsevier, Inc. Hemoglobin Dissociation Curve Alveoli –Over wide range hemoglobin will be highly saturated –Example: P O 2 of 60, saturation is 89% Tissue uptake –Normal: 5 ml O 2 /100 ml blood (40 mmHg) –Exercise: 15 ml O 2 /100 ml blood (20 mmHg)
Copyright © 2006 by Elsevier, Inc. Increased Blood Flow to Tissue Normal blood flow –20 ml O 2 / 100 ml blood * 5000 ml blood/min 1000 ml O 2 /min Increased blood flow –20 ml O 2 / 100 ml blood * ml blood/min 4000 ml O 2 /min
Copyright © 2006 by Elsevier, Inc. Carbon Monoxide Dissociation Curve P CO Per cent Saturation
Copyright © 2006 by Elsevier, Inc. Transport of Carbon Dioxide from Tissue CO 2 H 2 CO 3 H 2 O +CO 2 H CO H + H + +Hgb - HHgb Hgb Hgb. CO 2 carbonic anhydrase H CO 3 - Cl - CO 2
Copyright © 2006 by Elsevier, Inc. Carbon Dioxide Dissociation Curve Venous 52 vol% Arterial 48 vol% P CO 2 2 in blood volumes %