The heart, an important organ of the mammalian, operates as a pump. It is composed of two pumps: the right heart pumps the blood through the lungs while the left heart pumps the blood through peripheral organs. In turn, each of these separate pumps are composed of two pulsatile chambers, an atrium and a ventricle. Each minute, the heart of a resting adult pumps about 5 L of blood, or approximately the person's total blood volume. This works out to at least 720 Ll a day, the volume of blood weighting about 100 times more than the body. This heavy and incessant work is based on the fact that the heart muscle has a coordinated contraction. The cardiac muscle fibres are highly organized with strong inter-connections. A trigger pulse from the sinoatrial node, being the pacemaker, initiates and coordinates contraction, making possible the function of the heart as a pump and the contractility as the major parameter of the function of the heart.

atrium, cardilogy, contractility, myocardium, ventricle
P.R. Saxena (Pramod Ranjan)
Erasmus University Rotterdam
Netherlands Heart Foundation, Duphar Nederland BV,
Erasmus MC: University Medical Center Rotterdam

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