Discussion

"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 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 Erythrocytes (red blood cells), Leukocytes (white blood cells), Thrombocytes (platelets) and plasma.

"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 and then goes down to the right ventricule. The carbon dioxide is then carried to the lungs and to the left atrium and then down to the left ventricule. This the goes to the cells of the head and of the the body by the arteries.

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.

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 mouth and the nose, but respiration is achieved fully by the mouth, nose, trachea, lungs, and the diaphragm. This brings the O2 (Inhalation) to be replaced by CO2 (Exhalation).

"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."

All the systems in the body do their part and are really important. If you missed one of those systems or one system didn't work well, you wouldn't get to live really long since they all play a very important role in your body. The Excretory system is one of them. This system makes sure that the things that are not needed in your body gets out. The main products that this system takes care of or makes gets rid of is sweat, carbon dioxide and urine. Sweat contains 99% water and the other 1% is NaCl,Vitamin C, uric acid, urea, ammonia and lactic acid. Urine contains 95% water and the rest is waste like sweat. The sweat is caused by either stress, hotness or physical activities like sports or like our experiment that we did in science. In this case the sweat was caused by doing physical activities. The sweat is brought to the top of the skin by sweat glands all over your body who make sweat.In the experiment, almost everyone sweat because it is natural and also it makes your body cool down.

Blood pressure is really important. It is important for everyone to know what their blood pressureis so that if it isn't good, they can talk with their doctor. If you have low or high blood pressure, you will get symptoms of it. The normal blood pressure is to have the systolic pressure (right after the heart beats) at 120 and the diastolic (between the heart beats) at 80. If you have high blood pressure, the symptoms are headache, dizziness, blurred vision and nausea. These symptoms which comes from the high blood pressure can be caused by being overweight, sometimes if it has been in your family history, age (commonly over 50 but any age can get it), race like african-american, too much salt, smoking cigarette, alcohol, lack of physical activity and stress. The symptoms of low blood pressure are dizziness, fainting, difficulty concentrating, change in breath pattern, nausea and suddenly feeling cold or clammy. These symptoms which comes from the low blood pressure can be caused by pregnancy, some medication, heart problems, diabetes, dehydration, blood loss, severe infection and if you don't eat healthy and good. To know if you have low or high blood pressure, you should buy or use one of these machines:
Like all the other systems, the nervous system is really important, but this system is maybe even more important than the other sytems since it deals with telling the other systems what to do. Like when the cells miss oxygen, it will give the heart a really quick signal to advise it to pump faster to then make the respiratory and the other systems work harder to get more oxygen. In those cases the muscles around like the abdominal muscle will start to help breathing. A good example of that is when you run a cross country. The nervous system consists of a part of the brain, spinal cord, nerves, ganglia, and parts of the receptor and effector organs. The nervous system coordinates the body and controls a little bit. It is this system which gives signal to the other parts of the body when something doesn't work.