Exercise Physiology - lecture 4 Blood, gas exchange, transport
When the blood becomes warmer (e.g. in
active muscles) the curve shifts to the right.
This means that O2 has less affinity with
haemoglobin and is unloaded more easily.
When the blood becomes cooler (e.g. in the
lungs) this shifts the curve to the left. The
Hb has a higher affinity with O2, which
means there is a high level of O2 saturation.
CO2 Transport
Transported in blood in 3 forms:
1. dissolved in plasma (7-10%)
2. Binds to haemoglobin (different site to O2)
(carbaminohaemoglobin)
3. Transported as bicarbonate (60 70%)
In the active tissues:
H2O + CO2 H2CO3 HCO3- + H+
(carbonic bicarbonate
acid) ion)
CO2 Transport
In the lungs:
HCO3- + H+ H2CO3 H2O + CO2
Gas Exchange at the Muscles
-
a-vO2 Difference
Rest
This describes the extent to which O2 is extracted,
or removed, from the blood as it passes through the
body.
An increased a-vO2 difference represents a
annaabi.ee 
