Purkinje fibers

Purkinje fibers are specialized cardiac muscle cells in the heart that play a crucial role in the heart's electrical conduction system. They are named after the Czech anatomist Jan Evangelista Purkyně, who discovered them in 1839.

Structure

Purkinje fibers are located in the inner ventricular walls of the heart, just beneath the endocardium. These fibers are specialized myocardial cells that are larger than regular cardiac muscle cells, with fewer myofibrils and a large amount of glycogen. They also have a single, centrally located nucleus.

Function

The primary role of Purkinje fibers is to conduct electrical impulses from the atrioventricular node (AV node) to the ventricles of the heart. This rapid conduction of impulses allows the heart to contract in a coordinated manner, ensuring efficient pumping of blood throughout the body.

Clinical significance

Abnormalities in the Purkinje fibers can lead to various types of cardiac arrhythmias. For instance, damage to these fibers can result in bundle branch block, where the electrical impulse is delayed or blocked before it reaches the ventricles. This can lead to a slow or irregular heartbeat, known as bradycardia or tachycardia, respectively.

See also

• Cardiac muscle
• Cardiac conduction system
• Jan Evangelista Purkyně

References

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  Diagram of the heart's conduction system
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  Principle of ECG
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  Histology of endocardium and subendocardium