Publisher’s Blurb

Denis Noble chronicles the fascinating journey of his research into one of biology’s most essential functions — the Rhythmic Beating of the Heart.

For all animals that need a circulation to supply nutrients to the cells of the body a heart is needed to pump those fluids. The heart is therefore one of the first organs to start functioning even when the embryo is very small. In humans the heart starts beating around 28 days when the embryo is much less than a centimetre in size. It is essential that it should do so because molecules can rapidly diffuse only over very short distances, well before there is a functioning nervous system to control the other muscles of the body. So, how does the heart do that all by itself? All our skeletal muscles need the nervous system to make them contract. How the heart can beat spontaneously is what this book is about. The heart must somehow excite itself to start beating spontaneously without any nervous signal, and it continues to do that throughout life. The beat itself is mechanical, a strong muscular pump, but what triggers that forceful contraction is electrical.