The<unk>  transmits signals generated usually by the sinoatrial node to cause contraction of the<unk>  muscle. The pacemaking signal generated in the sinoatrial node travels through the right atrium to the atrioventricular node, along the Bundle of His and through bundle branches to cause contraction of the<unk>  muscle. This signal stimulates contraction first of the right and left atrium, and then the right and left ventricles. This process allows blood to be pumped throughout the body. The<unk><unk>  consists of specialised<unk>  muscle cells, and is situated within the myocardium. There is a skeleton of fibrous tissue that surrounds the<unk><unk>  which can be seen on an ECG. Dysfunction of the<unk><unk>  can cause irregular, fast, or slow<unk>  rhythms.
Electrical conduction system of the heart
Cardiac cycle
Coronary circulation
Parasympathetic nervous system
Myocardial contractility
Skeletal-muscle pump
Cardiac excitation-contraction coupling
Central chemoreceptors