BI 231 - Human Physiology and Anatomy
Cardiac Cycle, Valves, and Heart Sounds Study Guide

Compiled by Pat Bowne, Sherry Dollhopf,and Justin LaManna, 2007-11


The heart can pump blood effectively because of two things: first, its chambers contract at the proper time and rate, and second, valves keep the blood flowing one way only. The events that happen in a single heartbeat make up the cardiac cycle. One way we can measure whether they are happening properly is by listening to the sounds made by the valves.

Before class, make sure you:

Can describe the structure of the heart

Can trace the flow of blood through the heart

Tutorials and reading assignment:

Review the path of blood flow through the heart and body and the events of the cardiac cycle at:

You may also find this Auscultation Assistant Heart sounds web site useful:

Chapter 13, secs 13.3, 13.4, and 13.6

What you should know for the assessment:

Cardiac Cycle

Be able to list the steps of the cardiac cycle.

Which events result in systole and which events result in diastole?


Know the names (alternative names as well like mitral, semilunar, and atrioventricular) and location of all 4 heart valves.

Know the valve disorders we covered in class like regurgitations (insufficiencies) and stenotic valves

Be able to predict signs and symptoms associated with valve disorders we covered in class like an insufficient aortic valve.

Heart sounds

What are the two major heart sounds and what is causing the noise?

What is a heart murmur?

When during the cardiac cycle should you hear the first and second heart sounds?

Heart and cardiac cycle terms to memorize

Practice Questions

1. DEFINE systole and diastole

2. INTERPRET and EXPLAIN a graph of pressures in the different heart chambers during a cardiac cycle (Fig. 13.17)

3. TAKE the online quiz at:

4. Dr. Bob did his first open-heart surgery! He replaced the aortic semilunar valve in a man who had aortic regurgitation (a leaky valve that wouldnít close properly). Before his surgery, the man suffered from low blood pressure even though his heart rate was very fast. He looked pale all the time, was sweaty and anxious, and passed out a lot. So surgery was scheduled to replace his leaky valve with a valve that didnít leak. How did this manís valve problems cause his signs and symptoms? Dr. Bob put the new valve in upside down. Will this matter? Why or why not?

Practice question with example answer

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