Exam 23: Circulation

To evaluate cardiac function, scientists and physicians measure both the pressure and the volume inside the heart. When both pressure and volume data are plotted on the same graph, the resulting graph is called a pressure-volume loop. To create a pressure-volume loop, a catheter (a thin tube) is inserted into the vessels of the heart, and measurements of both left ventricular pressure and left ventricular volume are taken. The data are plotted on a graph, and cardiac function can then be evaluated from the distribution of the data and the shape of the loop. The following figure shows a typical left ventricle pressure-volume loop for a healthy young adult. The cardiac cycle proceeds counterclockwise. Each complete turn around the loop (for example, starting at point A and ending back at point A) represents one complete cardiac cycle. -If the time it takes to go around the loop is 1 second, what is the cardiac output in units of liters per minute?

In humans, which blood vessels have valves?

Which of the following can increase red blood cell concentration in a unit of blood?

Which of the following can contribute to high blood pressure?

Which of the following cells are phagocytes?

Which of the following factors contributes to the flow of blood in veins?

The largest blood vessel in the human body is the

Ron and Tiffany are studying circulatory system function. They designed an experiment to test whether the diameter of a tube affects the rate of flow through the tube. In their experiment, they ran water from a large container through five tubes with different diameters for exactly 30 seconds for each tube. They measured the volume of liquid that passed through the tube during the 30-second period, testing each tube three times and pouring the water back into the container after each test. The results of the experiment are shown in the following table. Diameter of Average Volume Tube () Fluid (mL) Tube A 0.5 210 Tube B 0.6 350 Tube C 0.7 480 Tube D 0.8 600 Tube E 0.9 975 -Ron and Tiffany modified the experiment to see how long it would take to pass 1,000 mL of fluid through each tube. Based on the results shown in the table, which tube would it take the longest for 1,000 mL of fluid to flow through?

Which of the following describes the stage of the cardiac cycle shown?

Ventricular contraction normally begins at the apex (bottom of the heart). What would likely happen if ventricular contraction originated at the intersection of the atria and the ventricles instead?

The diameter of a capillary is about the same as that of a(n)

Imagine that blood did not contain any dissolved proteins. What would likely happen when this abnormal blood flows through a capillary bed?

Bone marrow stem cells are sometimes used to treat certain blood cell diseases, such as

Which of the following molecules is least likely to be able to pass through a capillary wall?

Blood flow through capillaries is controlled by

Which of the following statements about red blood cells is true?

A man has been standing in one place without moving for a long time. You walk by and notice that his ankles are swollen. What is a likely explanation for this observation?

Which kind of vessel has the lowest blood velocity?

Sometimes when a person in a movie is stabbed or cut, blood forcefully sprays out of the wound. This is realistic only if the severed vessel is under a high degree of pressure. Which of the following vessels, if severed, would result in the most forceful spray of blood?

Cells make up about what percentage of total blood volume?