TRANSPORT OF RESPIRATORY GASES BY BLOOD
OXYGEN TRANSPORT Bound to hemoglobin Dissolved in plasma 1.5% of the oxygen transported is carried in the dissolved form. 98.5% of the oxygen is carried from lungsto tissues in a loose chemical combination with hemoglobin.
Association of Oxygen and Hemoglobin Hemoglobin is composed of four polypeptide chains. Each bound to an iron-containing heme group Four molecules of O2 Oxyhemoglobin HbO2 Reduced hemoglobin, or deoxyhemoglobin
The rate at which Hb reversibly binds or releases O2 is regulated by : PO2 temperature blood pH PCO2 organic chemical called BPG.
Influence of PO2 on Hemoglobin Saturation PO2 measurements indicate only the amount of O2 dissolved in plasma. PO2 values are a good index of lung function.