PEX 05 02

Exercise 5: Cardiovascular Dynamics: Activity 2: Studying the Effect of Blood Viscosity on Blood Flow Rate Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Which of the following is not a formed element? You correctly answered: c. plasma protein 2. Thrombocytopenia is a reduction in platelets. What effect do you think this could have on blood viscosity? You correctly answered: b. decrease blood viscosity 3. Which of the following does not contribute to the viscosity of the blood? You correctly answered: d. oxygen level in the blood 4. Viscosity most directly affects You correctly answered: b. peripheral resistance.

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Experiment Results Predict Question: Predict Question: What effect do you think increasing the viscosity will have on the fluid flow rate? Your answer : b. The fluid flow rate will increase. Stop & Think Questions: What is the relationship between fluid flow and viscosity? You correctly answered: b. They are inversely proportional to each other. What effect do you think aplastic anemia (reduced red blood cells) would have on blood flow? Your answer : b. decreased blood flow due to decreased viscosity Correct answer: a. increased blood flow due to decreased viscosity Experiment Data: Flow (ml/min) 490.6 245.3 163.5 122.7 98.1 81.8 70.1 61.3

Radius (mm) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0

Viscosity 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

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Length (mm) 50 50 50 50 50 50 50 50

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Pressure (mm Hg) 100 100 100 100 100 100 100 100

Post-lab Quiz Results You scored 50% by answering 2 out of 4 questions correctly. 1. The variable that you altered in this activity was Your answer: c. vessel radius. Correct answer: a. viscosity. 2. Increasing viscosity resulted in You correctly answered: b. decreased flow rate. 3. What effect would a decreased hematocrit have on blood flow? You correctly answered: d. decreased viscosity, increased flow 4. What do you predict would be the overall affect on viscosity during dehydration? Your answer: a. increased viscosity, increased flow Correct answer: b. increased viscosity, decreased flow

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Review Sheet Results 1. Describe the components in the blood that affect viscosity. Your answer: The formed elements and plasma proteins including leukocytes, erythrocytes, platelets, and proteins such as albumin. 2. Explain the effect that the viscosity change had on flow rate. How well did the results compare with your prediction? Your answer: The fluid flow increased. 3. Describe the graph of flow versus viscosity. Your answer: The graph was not linear, it was exponential. 4. Discuss the effect that polycythemia would have on viscosity and on blood flow. Your answer: Polycythemia is an increase in the RBC numbers. This would resut in an increase in viscosity and a corresponding decrease in flow.

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