second heart sound
The heart sound that signifies the beginning of diastole and is caused by closure of the semilunar valves.
Queen of HeartsRead more in this article about some frequently asked questions and fun facts related to our definitions.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.