[PhysioEX Chapter 5 exercise 7] PEX-05-07

Solved by ramonistry

Exercise 5: Cardiovascular Dynamics: Activity 7: Compensation in Pathological Cardiovascular Conditions Lab Report

Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.

Which of the following could cause an increase in peripheral resistance in the blood vessel?
You correctly answered: b. atherosclerosis
Which structures in the heart ensure that one-way flow occurs?
You correctly answered: d. valves
Which of the following might be seen in both the diseased heart and the athlete's heart?
You correctly answered: c. thicker myocardium
The type of resistance increased in aortic valve stenosis is
You correctly answered: d. increased left-ventricular afterload.

Experiment Results

Predict Question:
Predict Question 1: You will now test three mechanisms to compensate for the decrease in flow rate caused by the
decreased flow tube radius. Which mechanism do you think will have the greatest compensatory effect?
Your answer : c. decreasing the pressure in the right (destination) beaker
Predict Question 2: What do you think will happen if the pump pressure and the beaker pressure are the same?
Your answer : b. Flow rate will increase.

Stop & Think Questions:
Narrowing of the right flow tube radius simulates
You correctly answered: c. aortic valve stenosis.
What does increasing the pump pressure correspond to in the human heart?
You correctly answered: d. increasing the force of contraction
What does decreasing the right (destination) beaker correspond to in the human heart?
Your answer : d. increasing afterload
Correct answer: b. decreasing afterload

Experiment Data:
Condition Flow Rad. L Rad. R Str. V Rate Press. L Press. Dif. R
Normal 5086.8 3.0 3.0 70 72.7 40 40
Aortic stenosis 3310.0 3.0 2.5 70 47.3 40 40
Increased preload 3892.9 3.5 2.5 70 55.6 40 40
Increased preload 4256.7 4.0 2.5 70 60.8 40 40
Increased preload 4479.5 4.5 2.5 70 64.0 40 40
Increased contractility 3826.3 3.0 2.5 70 54.7 40 50
Increased contractility 4270.3 3.0 2.5 70 61.0 40 60
Decreased contractility 4656.3 3.0 2.5 70 66.5 40 70
Decreased afterload 3826.3 3.0 2.5 70 54.7 40 80
Decreased afterload 4270.3 3.0 2.5 70 61.0 40 60
Decreased afterload 4656.3 3.0 2.5 70 66.5 40 70

Post-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.

Which of the following compensatory mechanisms was not tested?
You correctly answered: c. decreasing the pressure in the left (source) beaker
In an actual heart, what is the most logical way to compensate for a decrease in flow tube radius?
You correctly answered: b. adjust the force of contraction of the heart
Without a difference in pressure between the pump and the destination beaker
You correctly answered: a. the valve will not open.
Athletes experience an overall __________ in peripheral resistance, so the heart generates __________ pressure to
deliver the same amount of blood. An athlete's arterial pressure would likely be __________ than that in a non-athlete.
You correctly answered: d. decrease, less, lower

Review Sheet Results

Explain how the heart could compensate for changes in peripheral resistance.
Your answer:
By increasing contractility.
Which mechanism had the greatest compensatory effect? How well did the results compare with your prediction?
Your answer:
Decrasing the pressure in the right beaker made biggest result as I predicted.
Explain what happened when the pump pressure and the beaker pressure were the same. How well did the results
compare with your prediction?
Your answer:
I failed with this question by misreading.. When there is no pressure gradient, there is no flow.
Explain whether it would be better to adjust heart rate or blood vessel diameter to achieve blood flow changes at a local
level (for example, in just the digestive system).
Your answer:
Adjusting blood vessel diameter is the best way to change blood flow cause the fourth power of diameter effect blood flow
which differs from others.