BIOS255 WEEK 1 Lab: #6 Effect of Exercise on Cardiac Output LABORATORY REPORT

PREDICTIONS

1. During exercise:

2: During exercise:

3. During exercise:

MATERIALS AND METHODS

1. Dependent Variable

2. Independent Variable

3. Controlled Variables

4. What instrument was used to measure cardiac volumes?

5. Does the instrument that was used to measure cardiac volume use X-rays? Explain.

RESULTS

See Table 2: Resting and Exercising Cardiac Cycle Length, EDV, and ESV
See Graph: Resting and Exercising HR, EDV, and ESV

1. Resting and exercising cardiac cycle length:

a. What was the average resting cardiac cycle length?

b. What was the average exercising cardiac cycle length?

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?

2. Resting and exercising EDV:

a. What was the average resting EDV?

b. What was the average exercising EDV?

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?

3. Resting and exercising ESV:

a. What was the average resting ESV?

b. What was the average exercising ESV?

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?

See Table 3: Resting and Exercising HR, SV, and CO
See Graph: Resting and Exercising SV and CO

4. Resting and exercising HR:

a. What was the average resting HR?

b. What was the average exercising HR?

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?

5. Resting and exercising SV:

a. What was the average resting SV?

b. What was the average exercising SV?

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?

6. Resting and exercising CO:

a. What was the average resting CO?

b. What was the average exercising CO?

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?

DISCUSSION

1. What caused the change in HR with exercise?

2. Discuss the effect of venous return and heart rate on exercise EDV.

3. What caused the change in ESV volume with exercise?

4. Why did SV change with exercise?

5. Discuss the importance of the change in CO with exercise?

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.

APPLICATION

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?

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.

3. Explain why elite athletes have a lower than normal heart rate, yet have a higher than normal ability to increase cardiac output.

1. The cause for the increased heart rate was related to need for more oxygenated blood to supply the need of the muscles for activity. The increased muscle activity caused an increase in CO2 and other waste products that need to be removed and new brought in to replenish in order to strive for homeostasis.

2. During exercise, the rhythmic pump of your muscles facilitates venous return by forcing blood through the one-way valves that lead to the heart. What's more, increased lung activity creates a change in thoracic pressure that draws blood toward your heart. Regular exercise improves venous return by increasing total blood volume, increasing end diastolic volume, and increasing the size and contractile strength of the heart muscle. Exercise also increases the number of capillaries at the muscle where oxygen and CO2 are exchanged, reducing peripheral resistance

3. A higher volume of blood being supplied out to the body and utilized at the peripheral capillary level.

4. Increased related to the raised pressure of the stressed heart to supply blood to the body.

5. With exercise there is an increase in the volume of blood being pumped by the heart each minute, which in return increases the cardiac output as well

6. My predictions that the HR will increase were correct. Heart rate increases with exercise as more blood is being pumped through the heart with each contraction. My prediction that the SV will increase was correct as the stroke Volume increases during exercise being that more blood is being ejected through the ventricles. And lastly my prediction that the CO would increase was also correct being that the volume of blood being pumped by the heart increased with exercise.

APPLICATION

1. The resting stroke volume is 70.34 and after exercising was 102.67

2. The amount of blood would be corrected with the next beat being that the volume of blood within each ventricle should remain almost equal to maintain normal function.

3. Athletes heart rate tend to be lower then the normal heart rate because they tend to pump a higher volume of blood with each contraction (cardiac output). This is due to conditioning of the heart from exercising and physical activity. Being that the body is getting the needed amount of blood, the heart doesn’t need to contract as much as a normal person.

Explanation: