MeSH definition : The sounds heard over the cardiac region produced by the functioning of the heart.
There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is
heard as a lubb sound; the second is produced by the closing of the AORTIC VALVE and
PULMONARY VALVE and is heard as a dupp sound; the third is produced by vibrations
of the ventricular walls when suddenly distended by the rush of blood from the HEART
ATRIA; and the fourth is produced by atrial contraction and ventricular filling.;
The sounds heard over the cardiac region produced by the functioning of the heart.
There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is
heard as a lubb sound; the second is produced by the closing of the AORTIC VALVE and
PULMONARY VALVE and is heard as a dupp sound; the third is produced by vibrations
of the ventricular walls when suddenly distended by the rush of blood from the HEART
ATRIA; and the fourth is produced by atrial contraction and ventricular filling.