Final answer:
Hyperpnea is an increased depth and rate of ventilation to meet an increase in oxygen demand, while hyperventilation is an increased ventilation rate that leads to low blood carbon dioxide levels and high blood pH.
Step-by-step explanation:
Hyperpnea is an increased depth and rate of ventilation to meet an increase in oxygen demand as might be seen in exercise or disease, particularly diseases that target the respiratory or digestive tracts. This does not significantly alter blood oxygen or carbon dioxide levels, but merely increases the depth and rate of ventilation to meet the demand of the cells. In contrast, hyperventilation is an increased ventilation rate that is independent of the cellular oxygen needs and leads to abnormally low blood carbon dioxide levels and high (alkaline) blood pH.