Human Biology, 14 Edition

Published by McGraw-Hill Education
ISBN 10: 1-25924-574-8
ISBN 13: 978-1-25924-574-9

Chapter 5 - Section 5.3 - The Heart Is a Double Pump - Check Your Progress - Page 100: 2

Answer

The "lub" sound that the heart makes is the sound of the cusps of the AV valves slamming shut due to increasing blood pressure in a ventricle. The "dub" is the sound of the semilunar valves closing as a result of blood in the arteries momentarily flowing backwards when the ventricles relax.

Work Step by Step

The "lub" sound that the heart makes is the sound of the cusps of the AV valves slamming shut due to increasing blood pressure in a ventricle. The "dub" is the sound of the semilunar valves closing as a result of blood in the arteries momentarily flowing backwards when the ventricles relax.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.

GradeSaver will pay $15 for your literature essays
GradeSaver will pay $25 for your college application essays
GradeSaver will pay $50 for your graduate school essays – Law, Business, or Medical
GradeSaver will pay $10 for your Community Note contributions
GradeSaver will pay $500 for your Textbook Answer contributions