Cardiac skeleton

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Cardiac skeleton, also known as the fibrous skeleton of the heart, is a complex structure composed of dense connective tissue that plays a crucial role in the anatomy and function of the heart. It provides structural support, isolates the atria from the ventricles electrically, and serves as an attachment point for the cardiac muscle, heart valves, and the origins and insertions of the great blood vessels.

Structure

The cardiac skeleton consists of four main components: the annulus fibrosus of the mitral valve and tricuspid valve, the trigona fibrosa, and the septum membranaceum. These components form a foundation that maintains the heart's shape, prevents overexpansion of the heart chambers, and anchors the valve cusps. The fibrous nature of the cardiac skeleton allows it to act as an electrical insulator, preventing the direct spread of electrical impulses from the atria to the ventricles, which is essential for the coordinated contraction of the heart.

Function

The primary functions of the cardiac skeleton include:

- Structural support: It provides a framework that maintains the anatomical integrity of the heart. - Electrical insulation: By isolating the atria from the ventricles, it ensures that electrical impulses travel through the proper pathways, specifically through the atrioventricular node and the bundle of His, to allow for coordinated contractions. - Attachment point: It serves as an anchor for the heart valves and the myocardium, facilitating efficient heart function. - Prevention of overstretching: It helps to prevent the overexpansion of the heart chambers during the filling phase.

Clinical Significance

Abnormalities in the cardiac skeleton can lead to various cardiac conditions. For example, calcification of the fibrous skeleton, particularly around the heart valves, can lead to valvular heart disease, affecting the flow of blood through the heart. Additionally, defects in the electrical insulation properties can result in arrhythmias, as the normal flow of electrical impulses through the heart is disrupted.

See Also

- Heart - Cardiac muscle - Valvular heart disease - Electrical conduction system of the heart