Practice Exercises for the Cardiovascular System

• On the diagram below, color the oxygen-rich blood red and the oxygen-poor blood blue. Label the parts:

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• Label the parts on the diagram below:

Study Questions on Anatomy Review: The Heart:

1. What's the difference between the blood in the right side of the heart and the left side of the heart?

2. a. Where does the blood go that is pumped out of the right heart?

b. What happens to the blood in the lungs?

c. Where does the blood go that is pumped out of the left heart?

3. What is the pulmonary circuit and the systemic circuit?

4. What three structural features are found on histological images of cardiac muscle?

5. What are the names of the two types of cell junctions in cardiac muscle cells?

6. What is the function of desmosomes?

7. What is the function of gap junctions?

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Intrinsic Conduction System

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Label the following graphic:

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• On the following diagram indicate where the following normally occur:

atrial depolarization, ventricular depolarization, ventricular repolarization, atrial repolarization

Study Questions on the Intrinsic Conduction System:

1. What is the purpose of the intrinsic conduction system of the heart?

2. What type of cells are present in the intrinsic conduction system of the heart?

3. List the six areas within the heart where autorhythmic cells are found.

4. Match the six areas within the heart where autorhythmic cells are found to their location within the heart.

Location Within the Heart:
a. Interatrial septum to the interventricular septum.
b. Lower interventricular septum to the myocardium of the ventricles.
c. Inferior interatrial septum.
d. Upper right atrium.
e. Throughout the walls of the atria.
f. Within the interventricular septum. / Areas Where Autorhythmic Cells Are Found:
Internodal Pathway
AV Node
Bundle Branches
SA Node
Purkinje Fibers
AV Bundle

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5. Match the six areas within the heart where autorhythmic cells are found to their function.

Functions:
a. Initiates the depolarization impulse that generates an action potential, setting the overall pace of the heartbeat.
b. Convey the action potential to the contractile cells of the ventricle.
c. Delays the action potential while the atria contract.
d. Links the SA node to the AV node, distributing the action potential to the contractile cells of the atria.
e. Electrically connects the atria and the ventricles, connecting the AV node to the Bundle Branches.
f. Conveys the action potential down the interventricular septum. / Areas Where Autorhythmic Cells Are Found:
Internodal Pathway
AV Node
Bundle Branches
SA Node
Purkinje Fibers
AV Bundle

6. Explain the difference between the electrical and mechanical events which occur within the heart, and explain the cell types that carry out each. Which occurs first, the electrical or mechanical events?

7. In an ECG tracing, how are the following represented:

a. atrial depolarization

b. atrial repolarization

c. ventricular depolarization

d. ventricular repolarization

8. Why is it important for the contraction of the ventricle to begin at the apex and move superiorly.

9. a. The P wave indicates the electrical event of atrial depolarization. What mechanical event follows the P wave?

b. The QRS complex indicates the electrical event of ventricular depolarization. What mechanical event follows the QRS complex?

c. The T wave indicates the electrical event of ventricular repolarization. What mechanical event follows the T wave ?

The Cardiac Cycle

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Study Questions on the Cardiac Cycle:

1. What is a cardiac cycle?

2. What opens and closes the heart valves?

3. List the three phases of the Cardiac Cycle.

4. Match the stages of the cardiac cycle to their description.

1a. Ventricular Filling: Passive / v. Ventricles contract and intraventricular pressure rises, closing the AV valves.
1b. Ventricular Filling: Atrial Contraction / w. Ventricles relax and ventricular pressure drops. Blood backflows, closing semilunar valves.
2a. Ventricular Systole: Isovolumetric Contraction / x. Blood flows passively into the atria, through open AV valves, and into the ventricles.
2b. Ventricular Systole: Ejection / y. Rising ventricular pressure forces semilunar valves open. Blood is ejected from the heart.
3. Isovolumetric Relaxation / z. Atria contract, forcing the remaining blood into the ventricles.

5. True or false: Blood passes through the bicuspid valve at the same time blood is also passing through the tricuspid valve.

6. What closes the AV valves?

7. What opens the semilunar valves?

8. What closes the semilunar valves?

9. What opens the AV valves?

10. True or false: The right side of the heart contracts, then the left side of the heart contract.

11. What is the relationship between pressure inside a chamber of the heart and the state of the heart muscle (relaxed or contracted)?

12. Blood always moves from ______pressure to ______pressure.

13. What causes heart valves to open and close?

14. Predict if the AV and semilunar valves are open or closed during the following phases of the cardiac cycle by circling the appropriate answer on this chart:

State of AV Valves / State of Semilunar Valves
Isovolumetric Contraction / Open Closed / Open Closed
Isovolumetric Relaxation / Open Closed / Open Closed
Ventricular Ejection / Open Closed / Open Closed
Ventricular Filling / Open Closed / Open Closed

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15. On the graph below, which letter corresponds to:

ventricular ejection isovolumetric relaxation ventricular filling isovolumetric contraction

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Cardiac Output

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Regulation of CO: HR

• Think about the effect increased sympathetic or parasympathetic input might have on heart rate.

• Fill out this chart, making note of the reasons for the increase or decrease:

Effect on Heart Rate
Increased sympathetic stimulation
Increased parasympathetic stimulation

Regulation of CO: SV

• Think about the effect increased sympathetic or parasympathetic input or venous return might have on stroke volume.

• Fill out this chart, making note of the reasons for the increase or decrease:

Effect on Stroke Volume
Increased sympathetic stimulation
Increased parasympathetic stimulation
Increased venous return

Study Questions on Cardiac Output:

1. Define cardiac output.

2. What two factors does cardiac output depend on?

3. What is the mathematical relationship between cardiac output, heart rate, and stroke volume.

4. Define heart rate.

5. What is the average heart rate in an adult at rest?

6. Define stroke volume.

7. What is the average stroke volume in an adult at rest?

8. Define end diastolic volume.

9. Define end systolic volume.

10. What is the mathematical relationship between end diastolic volume, end systolic volume, and stroke volume?

11. If the ESV is 50 ml and the EDV is 120 ml, what is the stroke volume?

12. If the heart rate is 75 beats per minute and the stroke volume is 70 ml per beat, then what is the cardiac output?

13. What's the relationship between venous return and stroke volume?

14. What is the effect of increased sympathetic activity on heart rate and stroke volume? How does this effect cardiac output?

15. What is the effect of increased parasympathetic activity on heart rate and stroke volume?

16. (Page 8.) What is the effect of a sudden loss of blood on heart rate and stroke volume?