10/29/2020 PhysioEx Exercise 5 Activity 1 PhysioEx Lab Report Exercise 5: Cardiovascular Dynamics Activity 1: Studying the Eﬀect of Blood Vessel Radius on Blood Flow Rate Name: Date: 29 October 2020 Pre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly. 1 Blood ﬂow is measured in You correctly answered: ml/min. 2 Which of the following has the greatest eﬀect on blood ﬂow? You correctly answered: blood vessel radius. 3 Which of the following would not result in a decrease in the blood vessel radius? You correctly answered: vasodilation. 4 The diameter of the blood vessel is the same as You correctly answered: two times the radius of the blood vessel. 5 The opening of the blood vessel where the blood ﬂows is called the You correctly answered: lumen. Experiment Results Predict Questions 1 Predict Question 1: What do you think will happen to the ﬂow rate if the radius is increased by 0.5 mm? Your answer: The ﬂow rate will increase. 2 Predict Question 2: Do you think a graph plotted with radius on the X-axis and ﬂow rate on the Y-axis will be linear (a straight line)? Your answer: no. Stop & Think Questions i 1/3 10/29/2020 PhysioEx Exercise 5 Activity 1 1 What is the driving force for blood ﬂow? You correctly answered: pressure gradient. 2 How does the body increase the blood vessel radius? You correctly answered: smooth muscle relaxation. Experiment Data Flow Rate (ml/min) Radius (mm) Viscosity Length (mm) Pressure (mm Hg) 4.0 1.5 1.0 50 100 12.6 2.0 1.0 50 100 30.7 2.5 1.0 50 100 63.6 3.0 1.0 50 100 117.8 3.5 1.0 50 100 201.0 4.0 1.0 50 100 321.9 4.5 1.0 50 100 490.6 5.0 1.0 50 100 Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1 The variable that you altered in this activity was You correctly answered: vessel radius. 2 Vessel radius and ﬂuid ﬂow i 2/3 10/29/2020 PhysioEx Exercise 5 Activity 1 You correctly answered: are directly proportional. 3 After a heavy meal, when we are relatively inactive, we might expect blood vessels in the skeletal muscles to be somewhat somewhat and the blood vessels in the digestive organs to be . You correctly answered: constricted, dilated. 4 When you increased the ﬂow tube radius, the ﬂuid ﬂow rate You correctly answered: increased. Review Sheet Results 1 Explain how the body establishes a pressure gradient for ﬂuid ﬂow. Your answer: By heart contraction, the pressure gradient is established. 2 Explain the eﬀect that the ﬂow tube radius change had on ﬂow rate. How well did the results compare with your prediction? Your answer: The ﬂow tube radius increased the ﬂow rate, as I predicted. 3 Describe the eﬀect that radius changes have on the laminar ﬂow of a ﬂuid. Your answer: When the radius increased, the ﬂow of ﬂuid is freer to ﬂow than when the radius is lower. The other way, when the radius is narrow the ﬂow of a ﬂuid is restricted and the rate is low. 4 Why do you think the plot was not linear? (Hint: look at the relationship of the variables in the equation). How well did the results compare with your prediction? Your answer: In the graph, the line is not straight, because the radius and ﬂow rate have not just a simple proportion. The ﬂow rate has a proportion with the fourth power of the radius. i 3/3