Investigating Human heart rate.

I will take my pulse at my neck on my carotid artery which is between the wind pipe and neck muscle, and just under the lower jaw bone. The pulse on the neck is easier to find than the radical on the wrist and this will be important as i will need to find it quickly to make my expiriment a fair test,

Hypothesis:

        Exercise creates stress on the heart to pump more blood to the muscles that are exercising. If the heart has to pump more blood faster the pulse rate will rise. My prediction is that the greater the amount of exercise the greater the pulse rate.

Obtaining Evidence:

My Results

For 5 Press Ups:

For 10 Press ups:

                

For 15 Press Ups:        

For 20 Press Ups:

For 25 Press ups:

Conclusion:

        I have discovered that pulse rate increases with exercise; pulse rate is higher after completing more vigorous exercise and trails of to a normal level soon after stopping exercise. As is shown by this graph:

        

My graphs show a sharp rise in pulse after commencing exercise and a slow drop after exercise, the graph above shows that more exercise you do for a longer time results in a much higher pulse rate and take longer for the pulse to return to normal rate (between 60 and 80). The results support my hypothesis as I predicted “Exercise creates stress on the heart to pump more blood to the muscles that are exercising. If the heart has to pump more blood faster the pulse rate will rise. My prediction is that the greater the amount of exercise the greater the pulse rate.” I have proved this hypothesis.

When the body is exercising the muscles respire to produce energy, so the muscles can contract. Oxygen is needed for this process; the oxygen is carried in the haemoglobin of the red blood cell. The heart and lungs need to work harder in order to get a greater amount of oxygen to the muscles for respiration. When muscles use oxygen in order to respire the process is called aerobic respiration: Glucose + Oxygen   →   Carbon Dioxide + Water

                     6C 12H 6O  +  6O  →    6CO  +  6H O

The heart rate rises because during exercise, cell respiration in the muscles increases, so the level of carbon dioxide in the blood rises. Carbon dioxide is slightly acid; the brain detects the rising acidity in the blood, the brain then sends a signal through the nervous system to the lungs to breathe faster and deeper. Gaseous exchange in the lungs increases allowing more oxygen into the circulatory system and removing more carbon dioxide. The brain then sends a signal to the heart to make the heart beat faster. As a result the heart rate would rise.