What should happen to pulse rate and blood pressure at 0,2,4,6,8,10 minutes, following a period of 5 minutes exercise and why?
Immediately after a five minute exercise, heart rate and blood pressure should be elevated significantly. How much they are elevated will be due to the overall physical fitness of the individual doing the exercise. Therefore, what we would observe would be a significant increase in heart rate and blood pressure at t=0 minutes. That's immediately after the five minutes of exercise. Then, at each time point along the way until we get to t=10, we would see a gradual decline in the heart rate and in the blood pressure towards the normal (or resting) rates.
Consider what happens during exercise. There is an increased contraction of the leg skeletal muscles and the diaphragm. These affect venous blood return to the heart. The skeletal muscle pump works more as the skeletal muscles contract more. When the skeletal muscles of the lower body contract, they tighten around the veins passing through them, which increases the venous blood pressure. As a result, the proximal valves open and this helps move the blood back to the heart. It works much like the action involved in milking a cow.
During deep breathing, the diaphragm moves downward which causes a decrease in the pressure in the thoracic cavity. But equally, there is a decrease in pressure in the abdominal cavity. As a result, a greater volume of blood moves from the compressed abdominal veins into the decompressed thoracic veins. Of course, when expiration occurs, the valves in the veins prevent backflow of the ...