C6H12O2 O2 C02 H20
The more work done by the muscles the more times respiration is needed to occur to provide the extra energy required. To get more energy you need more supplies of food (glucose) and oxygen.
Food is brought to the respiring cells in the plasma of the bloodstream, and the oxygen is transported as oxyhaemoglobin on the surface of the red blood cells. The heart pumps the blood around the body. If more work is done by the muscles energy is needed so more respiration occurs. To do this more oxygen and glucose is needed. Therefore because of high demand for oxygen and glucose the heart needs to beat faster to supply the cells with more oxygen and sugar so that it can provide the energy that is needed. This is why I predict that the heart rate will be much quicker where the muscles are working the hardest and the heart rate will be working the least in position 4.
METHOD
First the resting pulse rate will be taken and recorded. Then the person doing the experiment will get in to the body position for 2 minutes. After 2 minutes the person’s pulse rate will then be taken straight away and also recorded. The experiment will then be repeated but with a different body position.
FAIR TEST
To make sure this is a fair test I will:-
- Keep the time the person is in a certain body position constant.
- Make sure the pulse rate will be taken from the same place (on the wrist) and for the same length of time.
- Make sure the same person does the experiment, so the sex and body size does not affect the results. Some people might also be more fit than others.
- I should also try and make sure that before each body position experiment I have the same resting pulse rate.
- Do the experiment in the same room and at the same time to make sure temperature does not affect this experiment.
To make this experiment more accurate I will:-
- Repeat the experiment twice and then work out the average in beats per minute.
- Use a stopwatch.
- Be accurate when taking the pulse.
SAFETY
To make sure this experiment is safe and no one gets hurt I will:-
- Do the experiment where you can not hit anyone or be hit by anyone.
RESULTS
The chart shows the results that I obtained and I have calculated the average for each position. But now, I’m going to do a graph.
From my results and this graph we can see that each position has a different affect on the pulse.
Position 1:- Position 1 didn’t have a big affect on the pulse rate. I think this was because standing up doesn’t require your muscles to work really hard. Also you are used to standing up so therefore your muscles must also be used to this position.
Position 2:- This position also did not have a big affect on the pulse rate. But it was still a little more than position 1 (standing). The reason for this must be because your arms and legs are stretched to the side, so your muscles must have been working to keep the arms from dropping, so therefore your heart has to be pumping faster to get the blood to the muscles.
Position 3:- Position 3 has affected the heart rate the most. This must be because the muscles are contracting the hardest in this position, to keep you up because they have to work against gravity to keep you up. To deal with the great demand for energy the heart needs to pump faster to transport the oxygen and glucose to the cells and waste products away from the cells to avoid the build up of lactic acid, which is poisonous.
Position 4:- Position 4 made the heart rate slower. This was probably because in this position you are resting and most of your muscles are not working so there is no great demand for oxygen or glucose and therefore the heart does not need to work very hard to pump the blood around the body.
Position 5:- For this position the arm and leg muscles have to work very hard because the arms and legs are stretched outwards in the air. Therefore the muscles which stretch the arms and legs had to contract and work very hard resulting in a higher pulse rate.
Position 6:- This is a bit like position 5 but the arms and legs are not stretched out so muscles must not have been working very hard. This must be the reason why it does not affect the heart rate as much as position 5.
My prediction was right. Position 3 does increase the heart rate the most because this was the position where your muscles were working (contracting) the most so more oxygen and glucose were needed and therefore the faster the pulse rate to provide supplies of both, to the contracting muscles.
Conclusion
I think the data I collected were reliable. However the test could have been more reliable if I had done the entire test in one day, but there wasn’t enough time. It can also be very difficult to measure your heart rate because of human error. Other trivial things could also have caused inaccurate results like you may have been more tired after you did a few body positions. I could have also started with the same resting pulse rate each time, but I think it would have been very difficult to get your pulse rate at a certain rate every time.
But I still think that these results are accurate enough to come to the conclusion that different body positions do affect the heart rate, but different positions have a different affect. Different body positions make more muscles work than others, the greater the demand for energy, the more glucose and oxygen needed to produce the blood. These substances including waste products that are made like carbon dioxide and water are transported in the blood, which has to be pumped around the body by the heart. The heart has to keep up with the demands needed so it has to pump blood faster around the circulatory system to the cells of the muscles. But if there isn’t much of a demand for these products than the heart does not need to be pumped around the body as fast.
To improve this experiment next time I would wait longer for my pulse to return to normal. I would also investigate more positions to see if the same things happen and I would also extend it to find out if it differs for boys and girls.
