Final answer:
A build-up of slowing following hyperventilation is usually due to the body's efforts to restore normal blood carbon dioxide levels and pH, as well as the repayment of oxygen debt, which can influence various bodily functions.
Step-by-step explanation:
The cause for a build-up of slowing several minutes after hyperventilation has been completed might be attributed to various factors, including body temperature regulation, the repayment of oxygen debt, and the restoration of the physiological carbon dioxide levels in the blood. When a person hyperventilates, they expel carbon dioxide from their body at a faster rate than normal, which leads to a decrease in blood carbon dioxide levels and a rise in blood pH, making it more alkaline. After the hyperventilation stops, the body works to restore the carbon dioxide levels, and this process can cause a temporary slowing down of bodily functions. Additionally, exercise-induced hyperpnea is another instance where the breathing rate increases not solely due to oxygen demand, but also due to neural stimulation of respiratory centers in the brain, which can lead to a slower period following the cessation of the activity, similar to post-hyperventilation.