Discussion

During this experiment, many systems responded when the level of activity went up as you can see in the results. If one system was not there nothing would work. All the systems need to be there for your body to survive. All the systems work together to make one, if one isn't present you wouldn't be able to live for a long time.

The respiration and pulse rate went up, as the level of activity got higher, which was expected. The reason why the respiration and pulse got higher is because when the muscles are in heavy activity they require more oxygen. Since the muscles require more oxygen and since the way oxygen travels through your body is through the blood, the subject had to breathe in deeper and faster to be able to provided more oxygen for the muscles. The heart rate increased because it had to pump faster to make all the oxygenated blood go through the veins and to the muscles.

Each cell in the muscles needed more oxygen when doing more work because of increased cellular respiration within the cell.
Each cell also required glucose which is part of cellular respiration.
Two substances produced during cellular respiration are carbon dioxide and water. The cellular respiration formula is C6H12O6 + 6O2 ‡ 6CO2 + 6H2O + Energy.

Blood is the transport system for oxygen, glucose, carbon dioxide and part of the water. Blood is made up of plasma (55% of the blood), red blood cells white bloods cells and platelets.

Oxygen in the blood is carried by a system of tubules made-up of
arteries, arterioles, and capillaries. Oxygen diffuses from the high concentration in the arterial capillaries into the area of low concentration in the cell. Oxygen attaches itself to the erythrocytes that are red blood cells. Erythrocytes contain hemoglobin, which is a molecule that contains an iron atom. Oxygen binds itself to that iron atom.

Carbon dioxide diffuses from the high concentration in the cells into the area of low concentration in capillaries around the cell.
The capillaries carry the blood rich in carbon dioxide to the venules
and then to the veins. The veins carry the carbon dioxide to the upper and lower vena cava that lead into the right atrium, then to the right ventricle. Then, the carbon dioxide goes to the alveoli and then it reaches the bronchioles. After it goes up in the trachea, into the epiglottis where the carbon dioxide is getting out of the body from the nose or mouth.

Receptors, such as the one in the aorta, detect the rise in carbon
dioxide in the body as the blood leaves the left ventricle. The
carbon dioxide receptor examines the level of carbon dioxide in the blood. The receptor sends a signal to respiratory centre in response to an increase or decrease in the levels of carbon dioxide.
The respiratory centre is located in the medulla oblongata at the base of the brain.

The respiratory centre , which is part of the central nervous system
and part of the autonomous nervous system, sends a signal to the
muscles involved with respiration such as the intercostal muscles in the rib cage and the diaphragm to work faster if the levels of carbon dioxide have increased. These signals occur very quickly. During the intense activity level the abdominal muscles were also activated by the respiratory system. This was not part of the procedures so in the next repetition of the experiment this should be included in the procedures as one of the variables to observe.

As the muscles around the lungs contract, they enlarge the area around the lungs. The enlarged area around the lungs decreases the pressure in the lungs. The pressure outside the body is greater at that point than in the lungs so air from the outside is forced into the lungs by the difference in pressure. As the muscles relax and return to their original positions, the higher pressure on the lungs forces air from the lungs into the air.

The lungs are comprised of two main sections. The left and the right lungs. Air from the outside enters through the nose and mouth and then through the trachea. During inspiration, the diaphragm moves downward and becomes flatter and the rib cage expends. When the rib cage expends, it creates a small vacuum in the lungs and to equalize the pressure, the air is sucked in.

The results in the experiment indicate that both respiration and pulse increased with higher activity levels. The mean results support the hypothesis. The range in the results can be explained by different levels of strenuous activities, some requiring more oxygen, and by different levels of fitness among the subjects.

It would be worthwhile to add a further dimension to the experiment by analyzing how long it takes the body to resume the normal pulse and respiration to determine when oxygen levels returned back to normal. The hypothesis would be the faster that the subject's pulse and respiration returned to normal, the better
is the subject's cardiovascular and pulmonary systems. Another
addition to the experiment would be to have some subjects inhale
oxygen. The hypothesis would be that the subjects inhaling oxygen would return to their normal pulse and respiration rates faster than subjects who were not provided with oxygen.

The experiment could also test the level of carbon dioxide produced at the different levels of activity. This can be measured by having the subjects blow through a straw into lime water. Lime water turns murky white in the presence of carbon dioxide as done in a previous experiment this year. The faster the lime water turned milky white, the more carbon dioxide the subject must be exhaling.

The nervous system is very important. The nervous system are tuns of nerve cells and nerve fibers spread throughout the human body. The nervous system's role is to interpret, store, and respond to information received from inside and outside the body. The central nervous system, consists of the brain and spinal cord, which is responsible for processing information gathered from the rest of the nerves and transmitting instructions to the body. Messages passing from and to the central nervous system are carried by the nerves of the peripheral nervous system. This system has twelve pairs of cranial nerves and thirty-one pairs of spinal nerves. The cranial nerves and the spinal nerves control voluntary movements and sensations. The nervous system, consisting of sympathetic and parasympathetic nerve fibers, controls things in our bodies without us realizing it such as; the heart beat or us breathing while we're asleep. If the nervous system wasn't there for the intense activity, your sympathetic and parasympathetic nerve fibres would not have been there to tell your heart to pump faster or to tell you to breathe faster, which would probably lead to death because if your heart beat didn't increase then your muscles would not be receiving as much oxygen as it needs as the oxygenated blood would not be able to travel to the muscles fast enough and would probably not be oxygenated enough. The blood wouldn't be oxygenated enough because, your nervous system wouldn't have been there to make you breathe faster and deeper to bring in enough oxygen in your body.

The excretory system is also important. The excretory system is crucial to the body because the waste is poisonous, and if not disposed it would be really bad for you. In our experiment, the excretory system was used because for the intense activity many people were sweating, some more than others. The role of sweat (99% water and the other 1% is uric, NaCl acid, urea, ammonia, Vitamin C and lactic acid) is to help cool down the body temperature when the body reaches a high temperature.

The result for external temperature at rest was the lowest of the 3 level of activity. This is normal because at rest, your systems are not working that much as it is not needed. Surprisingly, the average result of external temperature for mild activity was higher to then the average of heavy activity. This may be because the subjects at mild activity did not have any sweat. Heat was exposed, so the temperature went up, but at heavy activity the subjects had a lot of sweat and the sweat (doing its job) was cooling down the temperature, therefore bringing the heavy activity external temperature lower than the mild activity temperature.