A heart beat is the rhythmic contraction and relaxation of the heart muscle, which pumps blood throughout the body. Each beat is initiated by electrical signals that travel through the heart, causing it to contract and push blood into the arteries. The average resting heart rate for adults ranges from 60 to 100 beats per minute. The heart has four chambers: the right atrium, right ventricle, left atrium, and left ventricle. Blood flows through these chambers in a specific order, ensuring efficient circulation. The heart's ability to maintain a steady beat is crucial for delivering oxygen and nutrients to the body's tissues.