The Heart Is a Pump…Our heart is a strong, hollow muscle that pumps blood day in and day out, resting only between beats. The arteries carry fresh blood containing oxygen to all parts of the body. The arteries supplying blood to the heart are called Coronary arteries.

There are four types of valves through which the blood flows on its journey through the heart. The opening and closing of the heart valves produces sounds which are termed as the heart beats. The opening produces the first heart sound called ‘Lubb’ and the closure is called ‘Dubb’. The valves open and close in sequence to allow the blood to pass in of the heart are the Tricuspid and Pulmonary valves.

On the left side are the Mitral and Aortic valves. The sounds that you hear when you listen to a heart beat are the sharp opening and closing of these valves.

The Circulatory System
The circulatory system provides the means of delivering oxygen and nutrient rich blood to each cell and transporting waste products to be removed from the body. The heart is the main pump and the engine of the circulatory system. The system includes:

• The Heart.
• The Lungs.
• The Arteries and Arterioles.
• The Capillaries.
• The Veins and Venules.

The Electrical System
Unlike other muscles in your body, the heart has its own way of controlling itself. It does not rely on signals from the brain in order to beat. It has its own electrical system (also called the conduction system) which controls the rate and rhythm of your heartbeat.

Sodium and potassium play an extremely important role in the conduction system of your heart. The electrical impulses in the heart are created when the charged ions of sodium and potassium pass through the walls of the cells in the heart. This movement creates a change in the charge of the cells which results in an electrical impulse. Specialized cells in the heart have the important job of transmitting this impulse throughout the heart in an organized manner. These specialized cells create an invisible electrical pathway in the heart. As the impulse moves along this pathway the muscle responds by contracting and pumping the blood.

There can be problems that arise with the heart’s electrical system. These problems change either the place from which the impulse originates and/or the pathway through which the impulse travels. This results in conduction disturbances called Arrhythmias.
The electrical conduction of the heart is observed with an electrocardiogram (ECG/EKG).