The primary function of the heart is to transport blood throughout the body, which delivers oxygen, nutrients and chemicals to the cells of the body to ensure their survival and proper function and to remove the cellular wastes. For the body to achieve this, it must maintain a certain blood pressure within the body to overcome gravity and orthostatic changes. If the body did not keep a certain pressure, distal cells and organs would not be able to receive a constant blood supply and cause a homeostatic imbalance. This experiment will show the possible changes in blood pressure due to gravity and orthostatic changes, but first, what is blood pressure and why is it important? Blood pressure is the force exerted by blood against a unit area of the blood vessel walls (Marieb, Hoehn 2013), and is measured in millimeters of mercury (mm Hg) with two different pressures, the systolic, which is the number on top, and the diastolic, the number on the bottom. The systolic pressure represents the amount of force being excreted during the peak of ventricular contraction, also the time when blood in being pumped into the arteries (Nelson, 2009). The diastolic pressure is the amount of pressure when the ventricles are relaxed (Nelson, 2009) and is always lower than the systolic pressure. Most physicians consider a blood pressure of 120/80 normal, but this is dependent on several factors, like overall health, medical problems, diet, age, and prescribed medications. Other pressures measured that are of importance to blood pressure are the mean arterial pressure (MAP) and the pulse pressure. The pulse pressure is the difference between the systolic and diastolic pressure and indicates the amount of blood being forced from the heart during systole (Nelson, 2012). Mean arterial pressure a term used in medicine to describe an average blood pressure in an individual during a single cardiac cycle (Sheps, Sheldon, 2003). Factors within the body that influence blood...
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