How does our heart beat without our doing it?

We asked Patricia Landry, M.D. She wrote, “The heart is a special type of muscle. Unlike the muscles of our arms and legs, the heart doesn’t have to be told to work. It beats all by itself. Inside the heart is a tiny spot with a collection of cells that keep sending electrical signals to make the heart beat. Automatic signals from the brain affect how fast the heart beats, but it is this little spot that makes the heart beat. The heart continues to beat even if it gets no signals from the brain. If a piece of a heart is cut off, the piece continues to beat. The heart has a heart to beat, and you can’t beat that."