Until I read this article I never knew exactly what regulated the heartbeat. Now I know that it is the vagal nerve. I always knew that something controlled this, it is so crucial to the performance of our bodies, but until now I had never heard of the vagal nerve.
I will have to more research on this because I am really fascinated. I guess we can think of the vagal nerve as a kind of internal metronome. It somehow contains an innate sense of rhythm. I wonder if this contributes to our broader sense of rhythm, the ability of most people to follow along with a beat? Maybe musicians and drummers especially have enlarged vagal nerves.