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David J. Orenstein FHRS, CEPS, CCDS, ECDSAP
Blood flow in the heart is done by the contraction of the heart muscle.
The cardiac cycle is divided into two periods:
Diastole - The ventricle muscle is relaxed
Systole - The ventricle muscle is contracted
The circulation of blood can be divided into two cycles: the Systemic Cycle and the Pulmonary Cycle.
The heart consists of four chambers:
Right and Left Atrium, and the Right and Left Ventricles.
The Atrium is connected to Ventricles via valves and the right and left sides are separated by a septum.
The heart consists of four key valves:
- Those between the Atrium and the Ventricles - On the right side the Tricuspid Valve (3 cusps), and on the left side Mitral Valve (2 cusps).
- Those between the Ventricles and out of the heart, commonly known as the Semilunar Valves (3 cusps) - On the right side the Pulmonary Valve and on the left side Aortic Valve.
The heart muscle itself is composed of different layers, which can be divided into three main layers (from outside to inside):