Gas transport to the periphery. Describe the transport of oxygen in the blood and understand the factors which alter the hemoglobin-oxygen dissociation curve. Review tissue oxygenation and causes of tissue hypoxia. Describe the transport of carbon dioxide in the blood and the carbon dioxide dissociation curve. Discuss carbon dioxide exchange in the lung and in the tissue.
Adult hemoglobin has two alpha and two beta chains.
Furthermore, normal hemoglobin A alters its ability to bind oxygen due to alterations in the spatial relationship of the heme and globin molecules. Oxygenation of one accelerates oxygenation of the remaining heme groups and similarly release of oxygen by one accelerates release by the others. Raising the PO2 above 100 mmHg will increase the oxygen content of the blood very little. If the HbO2 curve shifts to the left, i.e. decreasing the P50, then for any given PO2 the blood will be more saturated. If it shifts to the right then the P50 increases and for any given PO2, the blood will be less saturated.