"oxyhaemoglobin" - 1 õppematerjal

Exercise Physiology - lecture 4 Blood, gas exchange, transport

1. Dissolved in the blood plasma (less than 2%) · Assuming a total plasma V of 3-5 L, only ~ 9-15 ml O2 can be carried in a dissolved state. · Resting tissues require > 250ml O2 per min. 2. In combination with haemoglobin within the RBC (greater than 98%) · Haemoglobin within each of the 4-6 billion RBC allows blood to transport ~ 70 times more O2  Haemoglobin saturation 1 molecules haemoglobin = 4 molecules of O2 O2 + haemoglobin = oxyhaemoglobin Haemoglobin ­ oxygen = deoxyhaemoglobin Binding of O2 to Hb depends on PO2 in blood and the bonding strength (affinity) between Hb and O2. O2-hb disassociation curve Oxygen-haemoglobin Dissociation curve High drop in PO2 associated with only slight changes in O2 saturation. As PO2 of blood increases saturation increases. As PO2 of blood decreases