Control the heart rate

• Multicellular organisms require transport systems to supply their cells and remove waste products.
• In humans, one of the functions of the circulatory system is to transport substances.
• The heart is part of the circulatory system and its function is to pump blood.
• The heart beat is the sound of blood being pumped through the heart.
• The atria are the upper chambers of the heart which collect blood returning from the body or from the lungs.
• The right atrium of the heart collects blood returning from the body.
• The left atrium of the heart collects blood returning from the lungs.
• The atria of the heart generate electrical signals that make the heart contract independently of the nervous system.
• A group of specialised cells in the right atrium of the heart, known as the sinoatrial node, acts as a natural pacemaker.
• An artificial pacemaker is a medical device that uses electrical impulses to regulate heart beats.
• There are several types of artificial pacemaker, which have electrical leads connected to different chambers of the heart.
• Wires are guided along a vein to the chamber of the heart that needs to be stimulated.
• The lead extends to the pacemaker, which is fitted between the skin of the upper chest and the chest muscle.
• The fitting of artificial pacemakers is one of the most common types of heart surgery performed in the UK.