Variables Affecting Human Arterial Pressure and Pulse Rate
The woozy feeling when standing up too quickly. After going for a run, feeling as if one more beat and the heart would project itself out of the chest. Or quite the opposite and being in a very relaxed state. These are all changes one experiences at some time or another. What causes the different feelings and how each variable affects pulse rate and blood pressure has many wondering. Because of this curiosity, an experiment was performed to get some answers.
The purpose of the experiment is to see how different variables affect pulse rate and blood pressure.
Before starting the experiment, self educating on background information was a necessity in order to obtain a full understanding of what exactly was going to be performed. What is blood pressure and how does it work? “As the heart beats, the heart pushes blood through a network of blood vessels called arteries. As the blood travels through the arteries, it pushes against the sides of these blood vessels and the strength of this pushing is called blood pressure.” (Blood Pressure UK) After getting the basic definition of what blood pressure is, it was learned that when blood pressure is taken the first number that is said is the systolic blood pressure level or the highest level that is reached when the heart is squeezing. The second number that is read is the diastolic pressure level or the lowest level when the heart is relaxing, which is measured in mm Hg. (Blood Pressure UK) Moving on to pulse rate, also known as heart rate. It is known that pulse rate is the number of times the heart beats in one minute. (Gordon) Pulse is lower at rest and increases when higher activity is performed, like exercise. (Gordon) Pulse is taken by putting the tips of the index finger and middle finger onto the palm side of the opposite wrist below the base of the thumb. (Gordon) By pressing lightly with fingers, one could feel the blood pulsing beneath the fingers. (Gordon) After counting for ten seconds, the number of beats felt is multiplied by six to get the heart rate per minute. (Gordon) Normal pulse is between sixty and a hundred beats per minute. (Gordon)
Posture Changes, Exercise, and Cognitive Stressor are the three variables to be tested. First, the focus will be on posture changes. More specifically, reclining for three minutes. It is hypothesized that both, arterial pressure and pulse rate, will decrease because the heart doesn’t have to work as hard to distribute blood to the body. Normally it takes more effort to deliver blood to the body is erect. After reclining for three minutes and standing up quickly, it is hypothesized that pulse rate will decrease because the act of standing takes a good amount of blood that travels down into the legs causing less stroke volume for the ventricle to pump. Once standing for three minutes, it is hypothesized that the arterial pressure and pulse rate with both increase. As it is increasing, it will also be recognized that the arterial pressure and pulse rate will return to baseline.
Once data is collected from the variable of posture changes, exercise will be the next variable to look at. Immediately after exercising, it is hypothesized that arterial pressure and blood pressure will increase. It is thought because the body is performing high activity, it means that the heart has to work faster to be able to successfully perform venous return which then increases stroke volume and as a result increases cardiac output. Not only will the arterial pressure and pulse rate increase, it will be at its max range. Two minutes after exercise, it is hypothesized that the arterial pressure and pulse rate will decrease. Because the body is starting to calm down and come back down to resting, the heart doesn’t need to produce as high of stroke volume therefore decreasing the cardiac output.
Focusing on the...
References: Blood Pressure UK:
(n.d). Retrieved from http://www.bloodpressureuk.org/microsites/u40/Home/facts/Bloodpressure
Gordon, B. (n.d.). Retrieved from http://my.clevelandclinic.org/heart/prevention/exercise/pulsethr.aspx
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