Temperature and Oxygen Transport

  • Increased temperatures of blood result in a reduced affinity of hemoglobin for oxygen and thus a rightward shift of the Oxygen-Hemoglobin Dissociation Curve described in Oxygen Transport. Consequently, higher temperatures result in enhanced unloading of oxygen by hemoglobin. This relationship is helpful as metabolically-active peripheral tissues such as exercising skeletal muscle which often display supra-normal temperatures. Because of this increased temperature, oxygen unloading by hemoglobin is enhanced in these metabolically-active tissues, thus improving oxygen transport to areas which require it most.

Modulation of the Oxygen-Hemoglobin Dissociation Curve
A variety of environmental factors can shift the Oxygen-Hemoglobin Dissociation Curve. Effects which are associated with increased peripheral tissue metabolism, such as reduced pH, increased CO2, increased temperature, shift the curve to the right, reducing hemoglobin’s affinity for oxygen and thus improving oxygen unloading. Chronic hypoxia increases the blood’s concentration of 2,3-DPG which also shifts the curve to the right. The presence of HbF and carbon monoxide (CO) shift the curve to the left, increasing the oxygen affinity of hemoglobin.