1. During exercise HR will increase. 2. During exercise SV will decrease. 3. During exercise CO will increase.
Materials and Methods
1. Dependent Variable EDV, ESV, and cardiac cycle length 2. Independent Variable level of physical activity(resting or exercise) 3. Controlled Variables age, weight, height 4. What instrument was used to measure cardiac volumes? MRI 5. Does the instrument used to measure cardiac volume use X-Rays? Explain. no
Results Table 2: Resting and Exercising Cardiac Cycle Length, EDV, and ESV Resting Values Exercising Values Cardiac EDV (mL) ESV (mL) Cardiac EDV (mL) ESV (mL) cycle length cycle length (msec) (msec) 856 145 72 431 139 34 809 136 66 457 141 38 828 135 72 414 140 35 139 70 140 36
Subject 1 Subject 2 Subject 3 Averages
Resting and Exercising HR, EDV andESV
1. Resting and exercising cardiac cycle length -a. What was the average resting cardiac cycle length? 831 b. What was the average exercising cardiac cycle length? 434 c. The range of normal resting cardiac cycle length is between 818 and 858 ms. Did average cardiac cycle length increase, decrease, or not change with exercise? Decrease
2. Resting and exercising EDV -a. What was the average resting EDV? 139 b. What was the average exercising EDV? 140 c. The range of normal resting EDV
is between 135 and 145 ml for these subjects. Did average EDV increase, decrease, or not change with exercise? not change
3. Resting and exercising ESV -a. What was the average resting ESV? 70 b. What was the average exercising ESV? 36 c. The range of normal resting ESV is between 65 and 75 for these subjects. Did average ESV increase, decrease, or not change with exercise? decrease
Table 3: Resting and Exercising HR, SV and CO
HR (strokes per second) 70 74 72 72 Resting Values SV (mL) SV (L) 73 70 63 0.073 0.07 0.063 0.069 CO 5.1 5.2 4.5 4.9 HR (strokes per second) 139 131 145 138 Exercising Values SV (mL) SV (L) 105 103 105 0.105 0.103 0.105 0.104 CO 14.6 13.5 15.2 14
Subject 1 Subject 2 Subject 3 Averages
Resting and Exercising SV and CO
4. Resting and exercising HR – a. What was the average resting HR? 72 b. What was the average exercising HR? 138 c. The range of normal resting HR is between 70 and 73 beats per minute for these subjects. Did average HR increase, decrease, or not change with exercise? increase
5. Resting and exercising SV -a. What was the average resting SV? 69 b. What was the average exercising SV? 104 c. The range of normal resting SV is between 60 and 80 ml for these subjects. Did average SV increase, decrease, or not change with exercise? Increase
6. Resting and exercising CO – a. What was the average resting CO? 4.9 b. What was the average exercising CO? 14 c. The range of normal resting CO is between 4.2 L per minute and 5.84 L for these subjects. Did average CO increase, decrease, or not change with exercise? increase
1. What caused the change in HR with exercise? Muscles use more oxygen and glucose from the blood with increased movement. This produces wastes that decrease blood pH below the normal range causing an increase in heart rate. The heart rate increase delivers blood to the lungs and kidneys more quickly so these organs can remove the wastes from the body. The faster the muscles use energy and create waste, the faster the heart must pump blood.
2. Discuss the effect of venous return and heart rate on exercise EDV. Exercise increases venous return by forcing your body to add and enlarge blood vessels. In addition to circulatory improvements, exercise helps muscles and tissues become conditioned to allow them to overcome the stresses of working out. During exercise, the body demands additional oxygen and requires removal of extra carbon dioxide increasing the heart rate. EDV is increased with exercise 3. What caused the change in ESV volume with exercise? ESV decreases with exercising so that there is less resistance for the blood to flow to increase cardiac output. 4. Why did SV change with exercise? SV increase during exercise because an individuals body needs more oxygen and nourishment that are both received from the pumping of blood.
The level of increase of SV is also depends on the type of exercise 5. Discuss the importance of the change in CO with exercise? When the body is in rest cardiac output is lower as the demand in oxygen is low. During exercise heart rate and stroke volume increase which results in an increase in cardiac output 6. Restate your predictions that were correct and give data from your experiment that support them. Restate your predictions that were not correct and correct them, giving supporting data from your experiment that supports your corrections. My prediction were correct
1. We measured the stroke volume of the left ventricle. What was the average stroke volume of the right ventricle at rest and after exercise? 69 resting 104 exercising 2. Assume that for one beat, the stroke volume of the left ventricle is greater than that of the right ventricle. Explain why in a normal heart this would be corrected on the next beat. blood would be transferred from your systemic circulation into you pulmonary circulation.
Pressures throughout your pulmonary circulation would begin increasing. As soon as small amount of blood is transferred from the systemic to pulmonary circulation, the pressure in the pulmonary veins and left atrium increases a little. This increases the filling of the left ventricle, and the resulting increase in its end-diastolic volume increases the stroke volume, correcting the problem 3. Explain why elite athletes have a lower than normal heart rate, yet have a higher than normal ability to increase cardiac output. An athlete has a larger stroke volume, which means a greater volume of oxygen is delivered to the body per heartbeat.They usually have larger heart that results in higher cardiac output, as more blood is pumped out with each beat. The raised cardiac output allows the heart to beat more slowly