Reference no: EM13318127

The shift in the oxygen-hemoglobin dissociation curve with pH and PCO2 provides more oxygen available to tissues. As an example, consider the oxygen uptake by muscle tissue. The blood flow rate is 1 L/min under resting conditions. Arterial blood enters the muscle at PO2 = 100 mm Hg and PCO2 = 40 mm Hg at pH 7.4 and leaves at PO2 = 100 mm Hg and PCO2= 46 mm Hg and pH = 7.37. The pH within red cells in arterial blood is 7.27 and in venous blood the pH is 7.23. The P50 for oxygen binding to hemoglobin depends upon pH, temperature and PCO2 in the following manner: P50=26.8*10(0.4*(7.24-pH)+0.061*log(PCO2/40)+0.024*(T-37)) For this relation, the pH is the pH within red blood cells. The solubility of O2 in plasma is H = 1.34 x 10-9 mol cm-3 mm Hg-1. The solubility of O2 in hemoglobin in red cells is HHb = 1.50 x 10-9 mol cm-3 mm Hg-1. The hemoglobin concentration in red cells is 5.1 x 10-6 mol cm-3. a. For a hematocrit of 0.4, use the information provided above to calculate the oxygen uptake by the tissues. Examine the effect of the change in P50 by also calculating the oxygen uptake for the case in which the pH and PCO2 do not change along the length of the capillary.