Ex 5 Activity 3

Name: Rafeik Nessim Exercise 5: Cardiovascular Dynamics: Activity 3: Studying the Effect of Blood Vessel Length on Blood Flow Rate Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. When the length of the blood vessel increases, which of the following also increases? You correctly answered: d. both friction and surface area 2. Blood vessel length decreases You correctly answered: c. when we lose weight. 3. Blood flow is You correctly answered: b. directly proportional to vessel radius to the fourth power. 4. Which of the following correctly describes resistance to flow? You correctly answered: a. Resistance to flow increases with increased vessel length.

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Experiment Results Predict Question: Predict Question: What effect do you think increasing the flow tube length will have on the fluid flow rate? Your answer : c. The fluid flow rate will decrease. Stop & Think Questions: What is the relationship between fluid flow and flow tube length? You correctly answered: b. They are inversely proportional to each other. Which is more likely to occur on a daily basis? You correctly answered: b. changes in blood vessel diameter Experiment Data: Flow (ml/min) 90.8 60.6 45.4 36.3 30.3 26.0 22.7

Radius (mm) 3.0 3.0 3.0 3.0 3.0 3.0 3.0

Viscosity 3.5 3.5 3.5 3.5 3.5 3.5 3.5

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Length (mm) 10 15 20 25 30 35 40

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

Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Increasing the flow tube length is analogous to increasing blood vessel length. How did this affect the flow rate? You correctly answered: b. The flow rate decreased. 2. Which of the following correctly describes the relationships between blood vessel length, resistance, and blood flow? You correctly answered: c. Blood vessel length is directly proportional to resistance and inversely proportional to blood flow. 3. Which of the following correctly describes the relationships between blood vessel radius, resistance, and blood flow? You correctly answered: d. Blood vessel radius is inversely proportional to resistance and directly proportional to blood flow. 4. Which of the following describes why the body might require an increase in vessel radius? You correctly answered: a. to provide more blood flow and, therefore, nutrients to a particular body part

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Review Sheet Results 1. Which is more likely to occur, a change in blood vessel radius or a change in blood vessel length? Explain why. Your answer: A change in blood vessel radius is more likely to occur than a change in blood vessel length. A change in blood vessel radius only requires the contraction of relaxation of the smooth muscles surrounding the vessel, while a change in blood vessel length requires creating more cells and vessel tissue to increase its length. 2. Explain the effect that the change in blood vessel length had on flow rate. How well did the results compare with your prediction? Your answer: Blood flow decreased as vessel length increased. This is what was predicted by the equation. As the vessel length increases the resistance increases, and consequently the flow decreases. This matches with the predictions made during the experiment. 3. Explain why you think blood vessel radius can have a larger effect on the body than changes in blood vessel length (use the blood flow equation). Your answer: Vessel radius has a greater impact on blood flow. Because as the equation states, the vessel radius is to the power of 4 while the vessel length is to the power of 1. 4. Describe the effect that obesity would have on blood flow and why. Your answer: When a person gains weight the blood vessels length increase to accomodate delivering blood to all the tissues. When blood vessels length increase the resistance increases and consequently blood flow decreases, which could very possibly causes health issues.

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