Respiratory Bio Lab Report

Bio Lab: The Effect of Exercise on The Respiratory and Circulatory Systems
Ellie Cookson

Communication:

2. As the graphs show, both breathing rates and pulse rates spike significantly between the resting rates and immediately after exercise. Average breathing rates went from 26.7 breaths/min at sitting rate to 46.4 breaths/min during or immediately after exercise. Pulse rates also increased quite dramatically, going from an average of 65 beats/min at rest rate to an average of 100.3 beats/min after exercise. As the participant exercised for a longer period of time, a change in skin colouration was noticed. Faces flushed to a pink colour at first and then progressed into a darker red as exercise continued. It was also noted that
at first, or in early parts of the exercise, there was generally no flushing or perspiration but as time increased, flushing would start and perspiration would start to appear of foreheads, upper lips, back of necks etc. This is because at the beginning of the exercise, the body has not yet heated up that much but as the length of exercise time increased, the body temperature did too, causing the body to initiate flushing and sweating mechanisms to cool body down. After exercise ended, breathing rates decreased quite rapidly, going from 46 breaths/min to 34 after one minute. Graph 1 shows that it took about 3-4 minutes for breathing rates to return to resting rate. Pulse rates however, took longer to return to resting rate: around 9-8 minutes. As time after exercise increased, flushing of the skin reduced and the perspiration stopped.

Application Questions:

1. The resting pulse and breathing rate is used as a control variable to compare results against. Since the resting rates are what people are at usually, it is easier to see the differences between when one is at rest and when one is exercising. If we didn’t take results at sitting rate, we could not see the difference exercise makes to breathing rate and pulse rate. 2. During exercise, cellular respiration increases to create energy in the form of ATP and glucose to be used by the body to sustain the exercise. For this they need increased levels of oxygen to carry out the respiration. Your breathing rate goes up because the body needs to suck in more oxygen to supply the muscles with the levels they need. Since more energy is being created, more waste carbon dioxide is created resulting in breathing rates also going up to make sure all the extra CO2 is expelled. The heart is the muscle that pumps blood around your body. Blood contains the oxygen from the lungs that needs to get to the muscles and also carries the waste CO2 back out to the lungs and out the body. Since the amounts of oxygen needed and carbon dioxide waste are increasing, the heart pumps faster to get the blood with necessary gases around more efficiently and in more volume. 3. As fitness increases, breathing rates slow down because the lungs become more accustomed to the amount of oxygen needed. Breaths become more voluminous so you don’t need to take as many breaths as someone less fit to get the same amount of oxygen. Your breathing muscles--the intercostals and diaphragm--become stronger and there is an increase in capillary density at your alveoli to allow for greater diffusion of oxygen into your blood and removal of carbon dioxide from your blood. Increased fitness also means that one can deliver more blood to the body in one cardiac cycle than an unfit person meaning there would more oxygen and CO2 going around with less beats which results in a slower heart rate during exercise. 4. A fitter person’s heart rate would return to normal faster than an unfit person because of the nervous systems that control the heart. As fitness increases, time needed to recover decreases because your body becomes trained and more efficient to lower heart rate quicker. Also, since your heart rate is generally already lower during exercise if you are physically fit, then it would take less time to return to normal rate. 5. a) Sweating activates a mechanism to help keep body temperature within a range that is acceptable for efficient function. The brain tells the body to sweat to help cool it down. Sweating works by triggering the sweat glands to begin producing sweat. As it accumulates, it is released from the skin pores to the surface. Sweating cools the body by forcing the excess heat to be redirected to a specific task, that of evaporating the water from the sweat off of your skin.
b) To regulate body temperature, your body signals more blood to flow to the skin's surface. This actually creates more heat on the skin's surface which will then be radiated off the skin. Since the heat is being radiated off the skin and out of the body, flushing is an efficient mechanism to cool down the body. 6. After eating, a significant about of blood flow is directed to the stomach and other digestive organs to make sure the food is digested completed. When you exercise right after eating, the blood needed to digest the food is now redirected to the muscles, leaving the food not fully digested. This will cause possibly severe abdominal cramping, which can be dangerous in some forms of exercise. 7.
Homeostasis is the balance of all vital life systems within the body. Your body reacts to the environment it is in so that it can adapt to maintain a constant internal balance aka maintain homeostasis. During exercise, many processes are adapted to make sure your internal balance is constant. Muscles need more oxygen to create the ATP required to sustain muscle movement and so the breathing rate increases to increase oxygen. The extra oxygen will return equilibrium to the body because the amount of oxygen now matches the amount that the cells need. Lack of oxygen will throw homeostasis off balance and can result in severe cell damage. Since more oxygen is needed, the heart must also adapt to these demands and will pump the extra-oxygenated blood faster around the body. This results in heart rate going up to maintain the balance of oxygen getting to the cells and CO2 being removed. It also pumps faster to make sure that the balance between oxygen and waste CO2 stays constant. More oxygen is needed but also more waste CO2 is being created so the heart must beat faster to get the blood around the body to expel the waste. If it doesn’t speed up then there could be a buildup of CO2 or lack of oxygen, which would throw off the homeostasis. Homeostasis also makes sure that the body has a constant internal temperature, usually 37 degrees. Sweating and skin coloration both relate to homeostasis because they are both mechanisms to cool the body down. When exercising, body temperature tends to increase because of the amount of work being done by the internal systems. This is why sweating and skin coloration is needed. Skin coloration makes sure that heat from the body is being radiated off the body by making the blood flow closer to the skin and sweating uses excess heat to evaporate the sweat off the body, resulting in a cooling effect. Both of these mechanisms are used during exercise to make sure that the body does not overheat and maintains the constant internal
temperature and thus maintains homeostasis.