Physiology Lab Report
The Effects of Exercise on the Cardiovascular System
Exercise has a major impact on the cardiovascular system and its efficiency in the human body. There are many concepts which need to be examined to understand exercise and the cardiovascular system, such as systolic and diastolic blood pressure, cardiac output, total peripheral resistance, and physiological pathways. According to the European Journal of Cardiovascular Prevention and Rehabilitation, exercise provides a change in the effectiveness of the cardiovascular system, whether over a short or long period of time (Lamotte et al. 2009).
Systolic blood pressure is maximal arterial pressure during peak ventricular ejection, while diastolic pressure is minimal arterial pressure that takes place just before ventricular ejection (Widimaer et al. 2008). Cardiac output is defined as the volume of blood pumped by each ventricle per minute (Widimaer et al. 2008). Cardiac Output can be calculated using the formula: CO=HRxSV, where CO is the cardiac output, HR is the heart rate, and SV is the stroke volume (Widimaer et al. 2008). Stroke volume is the amount of blood pumped by the left ventricle of the heart in one contraction (Widimaer et al. 2008). Total peripheral resistance is the sum of the resistance to flow by all the systemic blood vessels (Widimaer et al. 2008). Total peripheral resistance (TPR) is the resistance to blood flow because of friction between blood and vessel walls. TPR and blood pressure are directly proportional in that when TPR increases, blood pressure also increases (Widimaer et al. 2008). Cardiac output is also directly proportional to blood pressure. Cardiac output and total peripheral resistance pair to create blood pressure in that the amount blood flowing through a vessel and the resistance to the blood from the vessel walls create blood pressure.
Hormonal and neural pathways also control blood pressure in that they bind to receptors to alter arteriolar radius. Norepinephrine and epinephrine bind to α-adrenergic receptors on arteriolar smooth muscle to cause vasoconstriction or vasodilation (Widimaer et al. 2008). Other hormones that affect the arteriolar radius and increase vasoconstriction are angiotensin II and vasopressin (Widimaer et al. 2008). The nervous system affects blood pressure and heart rate in that the sympathetic nervous system regulates end-diastolic pressure by playing a part in regulating stroke volume (Widimaer et al. 2008) Also, heart rate is controlled by both the sympathetic and parasympathetic components of the autonomic nervous system (Widimaer et al. 2008). The sympathetic nervous system releases norepinephrine and epinephrine, which increases heart rate. The parasympathetic nervous system releases acetylcholine, which decreases heart rate.
While exercising, the cardiac output of the heart is increased. This increases the total amount of blood volume that is pumped around the systemic circuit (Widimaer et al. 2008). Therefore, exercise produces a rise in metabolic activity in the body, which causes an increase in blood pressure (Pickering et al. 1982). However, over time exercise can lower systolic and diastolic blood pressure (Widimaer et al. 2008).
The purpose of this experiment is to find how exercise affects heart rate, systolic, and diastolic pressure. The results will show that immediately after exercise, heart rate and systolic pressure will increase, while diastolic pressure will stay the same. Materials and Methods
First, the class recorded pre-exercise heart rate in BPM (beats per minute), as well as systolic and diastolic pressure (in mmHg) at rest. This was taken using an automatic cuff. Second, the class ran one at a time from the fourth floor up to the fifth floor, back down to the first floor, and then back up to the fourth floor. The class was instructed to run at 75% of maximum rate. After each classmate returned from running, post-exercise...
Cited: Lamotte, Michel, Fany Fleury, Melissa Pirard, Alexander Jamon, and Philippe van de Borne. 2009. Acute cardiovascular response to resistance training during cardiac rehabilitation: effect of repetition speed and rest periods. European Journal of Cardiovascular Prevention and Rehabilitation. 17.3:329-336.
Physiology: The Mechanisms of Body Function. 11th ed. New York: McGraw-Hill Companies, 2007. Print.
Pickering, Thomas G., Gregory A. Harshfield, Hollis D. Kleinert, Seymour Blank, and John H. Laragh. 1982. Blood pressure during normal daily activities, sleep, and exercise. The Journal of the American Medical Association 247.7:992-996.
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