Assignment 1

1 .		A number of different conditions can influence blood viscosity. For example, blood viscosity will decrease due to a decrease in the number of red blood cells in the condition known as anemia. Conversely, individuals living at higher altitudes often experience polycythemia—an abnormal increase in red blood cell count. Polycythemia occurs in response to reduced oxygen content of the atmosphere at higher altitudes. Both decreases and increases in blood viscosity strongly influence MAP. Develop a hypothesis below to predict the effect of an increase in blood viscosity on blood pressure.
2 .		Click and drag on the slider to increase blood viscosity. What happened to MAP? Does this make sense to you? Explain your observations and relate them to your hypothesis.
3 .		Use the slider to decrease blood viscosity and observe what happens to MAP. What happened to MAP? Does this make sense to you? Explain your observations and relate them to your hypothesis.
4 .		Formulate a hypothesis below to predict the effect of an increase in blood vessel radius on MAP. Formulate a separate hypothesis to predict the effect of a decrease in blood vessel radius on MAP.
5 .		Test each hypothesis by using the slider to change blood vessel radius and follow the effects of these changes on MAP. What happened to MAP after each change? Do these effects make sense to you? Explain your observations.
6 .		In the cardiovascular disease called arteriosclerosis ("hardening of the arteries"), the deposition of saturated fats and cholesterol along the inner lining of blood vessels reduces vessel diameter. Simulate this condition and explain what happens to MAP.
7 .		Formulate a hypothesis to predict the effect of an increase in heart rate on cardiac output and MAP. Formulate a separate hypothesis to predict the effect of a decrease in heart rate on cardiac output and MAP. Describe your hypotheses below.
8 .		Test each hypothesis by using the slider to change heart rate and follow the effects of these changes on cardiac output and MAP. What happened to cardiac output after each change? What happened to MAP after each change? Do these effects make sense to you? Explain your observations.
9 .		Increase stroke volume by increasing diastolic ventricular volume, then observe what happens to cardiac output and MAP. Explain why increasing diastolic ventricular volume produced an increase in stroke volume. What happened to cardiac output and MAP when stroke volume was increased?
10 .		Based on what you know about stroke volume, what is another way that stroke volume can be increased using CardioLab? Once you have answered this question, use CardioLab to verify or refute your answer.