Question

Discuss the changes in the cardiovascular and respiratory system during and just after a 100 meters sprint, in the context of

1. Changes occur compared to resting
2. Interactions between these systems
3. What are the local regulatory mechanisms and how those respond to exercise?

• Keep your answer under 1500 characters (spaces not included).
• You can use/draw a diagram or figure in addition to your answer.

Answer 1

The rate of heart beat (in cardiovascular system) and rate of respiration increases during the 100 meter sprint and also it remains the same just after the sprint too. But gradually the rate of heart beat and the rate of respiration decreases up to normal level after exercise with passing of time.

As during the running, the cells of our muscles requires more energy than the normal level. For this purpose the rate of respiration increases in the muscle cells during exercise and more carbon dioxide is produced. The increase in the amount of carbon dioxide production decreases the pH of blood which in turn stimulates the medulla oblongata to increase the rate of breathing. So that the extra amount of produced carbon dioxide from the blood can be excreted and sufficient amount of oxygen can be provided to the muscle cells. The sympathetic nervous system releases adrenaline and hence the rate of heart beat increases and subsequently the rate of blood flow through the blood vessels too.

Just after the run also, the cells of the muscles requires more energy than the normal level as the metabolic processes in the cells are still high. So the heart beats and rate of respiration remains high just after the run and both comes to normal level with passing of time.

As per the passing of time the blood carbon dioxide level decreases and hence the rate of heart beat and rate of respiration decreases by stimulating the medulla oblongata and secretion from the parasympathetic nervous system ( acetylcholine) accordingly.