[Master Answer Logo]
Question

Why is the heart blue?

Answer

The heart sounds are the noises (sound) generated by the beating heart and the resultant flow of blood through it. This is also called a heartbeat. In cardiac auscultation, an examiner uses a stethoscope to listen for these sounds, which include heart tones, or sounds, produced by sudden blood deceleration after the heart valves close, heart murmurs, and adventitious sounds, or clicks.

— Source: Wikipedia (www.wikipedia.org)