Ventilation-perfusion inequalities

1. Describe the gravity dependent processes which affect pulmonary blood flow. What changes take place when the pressure increases in the pulmonary vessels? (97A2)
2. Compare the effect on arterial blood CO2 and O2 levels of ventilation/perfusion inequalities (1997) 
3. Define 'Venous Admixture'. Briefly explain how venous admixture influences arterial O2 tension and how an increase in inspired O2 concentration may affect this. (02A3) (95B1)