2. H.6.1 Define partial pressure.
H.6.2 Explain the oxygen dissociation curves of adult
hemoglobin, fetal hemoglobin and myoglobin.
H.6.4 Explain the role of the Bohr shift in the supply of
oxygen to respiring tissues.
3. H.6.3 Describe how carbon dioxide is carried by the
blood, including the action of carbonic anhydrase, the
chloride shift and buffering by plasma proteins.
H.6.5 Explain how and why ventilation rate varies with
exercise.
Limit this to the effects of changes in carbon dioxide
concentration leading to a lowering of blood pH. This is
detected by chemosensors in the aorta and carotid
arteries that send impulses to the breathing centre of
the brain. Nerve impulses are then sent to the
diaphragm and the intercostal muscles to increase
contraction or relaxation rates.
4. H.6.6 Outline the possible causes of asthma and its
effects on the gas exchange system.
H.6.7 Explain the problem of gas exchange at high
altitudes and the way the body acclimatizes.
