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.
C6H12O6+ 6O2 --> 6CO2 + 6CH2O
Blood is the transport system for oxygen, glucose, carbon dioxide and part of the water. Blood contains Platelets, Plasma, white blood cells and red blood cells. Plasma is the liquid part of the blood. It carries substances around the body. It transports the products of digestion, carbon dioxide, and urea etc. It controls the pressure of the bloodstream. Red blood cells are the most common type of blood cell; they are responsible for the transport of oxygen to the cells and carbon dioxide back to the lungs. Plasma transports materials needed by cells and materials that must be removed from cells. White blood cells defend the body of infectious diseases.
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. Arteries carry oxygenated blood away from the heart and deliver it to the bodies arterioles and capillaries, where the oxygen is consumed. Afterwards the venules, and veins carry deoxygenated blood back to the heart.
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. From the atrium the Co2 goes in and out of the pulmonary artery. The carbon dioxide then comes back to the heart through the pulmonary veins into the left atrium. It circulates to the left ventricle and out the aorta. From there the carbon dioxide reaches the bronchioles. When it is done in the bronchioles it goes up in the trachea, into the epiglottis where it is released by through 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. When you exercise, this is why you breathe harder and faster. Your body automatically wants more oxygen and it sends a message to the respiratory centre. This deeply increases beathing, which causes exhaustion.
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 consist of two main sections, the left and right lungs. Air Then the oxygen passes through small passages called the Bronchioles. The air then goes to the Alveoli. This is where the gases are exchanged in the respiratory system. Your blood takes in more oxygen in exchange for the carbon dioxide, which you then exhale.
Several organs are involved with the excretory system, including the kidneys, sweat glands, lungs and rectum. The primary organs of excretions, however, are the kidneys. Excretion is vital to the health of the body because the wastes are poisonous. If the wastes build up and are not eliminated, they can cause serious problems. As you know, the lungs remove carbon dioxide and water vapor. The kidneys and sweat glands remove other wastes, namely urea, uric acid, various salts, and assorted nitrogenous wastes. In this experiment we observe an increase of sweat when exercising harder. This is because more excretions such as nitrogen and various salts need to be removed. Without sweat glands we wouldn’t be able to get rid of certain excretions.
Every System is crucial for a normal body function, without the help of one; the whole body would slowly break down. For example, if the human body would not have the pulmonary system, the body would not be able to breathe. Each system needs the other systems to function as needed.
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.
