Cardiovascular system Essay Example | Topics and Well Written Essays - 2500 words

Cardiovascular system - Essay Example Demonstrate the adaptability of the cardiovascular system to autoregulate to two different, stressful conditions (1. Max test 2. Steady state exercise at 65% maximum oxygen level). Explain in detail how the different cardiovascular components such as heart rate, systolic blood pressure, diastolic blood pressure, total pulmonary resistance, stroke volume and blood flow, respond to these stressful conditions. Explain in detail the physiological mechanisms responsible for the changes observed.The cardiovascular system has the capabilities to adapt to a number of external factors. An example of the cardiovascular system’s ability to adapt is seen in response to a max test. This test measures the volume of oxygen in the blood that the body uses in one minute of maximal exercise. A stationary exercise machine is used when administering the test. The first-minute interval is done at a very easy level. As each minute passes the levels become increasingly more difficult until you reach a levels when you can no longer continue. The max test requires you to wear a mask and to breathe through your mouth. The mask is connected to an analyzer that looks at the levels of carbon dioxide and oxygen in the exhaled gas. You are also hooked up to a heart monitor. Using the information gathered you could figure out your cardiovascular fitness and define your maximum aerobic power.The max test causes an increase in heart rate, because there is an increased need by your muscles for oxygenated blood ... stroke volume in this case would decrease due to the fact that the peripheral vessels, which have higher pressures, increases. The increased heart rate causes the ventricles to not fill as full, thus lowering the volume pumped out of the ventricles by each contraction. The final stage of the max test is anaerobic. This stage looks at how quickly the body can remove the lactic acid. The increased heart rate helps in the removal of lactic acid. If you have crossed this threshold you will be prematurely fatigued and may feel your muscles burn. Toga et al. states that "during hypoxia, the total" pulmonary "resistance decreased with increased blood flow" (Effects of hypoxia, 1998, 1003). Steady state exercise is different from the max text, because it does not increase in intervals. In the steady state test you also have the increase in systolic blood pressure, but there is no dramatic increase in diastolic blood pressure. When steady state exercise has been done over time the effects are a minimal change in blood pressure and a higher red blood cell count (blood is more easily saturated with oxygen). Once finished with steady state exercise the systolic blood pressure will drop to below normal levels for a brief period of time. Steady state exercise, when done on a regular basis, will decrease heart rate. A decrease in heart rate will allow the ventricles more time to fill. . Stroke volume is the volume of blood in the ventricles during diastole minus the volume of blood in the ventricles during systole of the same heartbeat. If the heart rate is slower it allows for more filling of the ventricles hence a larger stroke volume. There are other factors that also contribute to these different cardiovascular components. Khaksari et al.