What is the role of Purkinje fibres in heart?

Purkinje fibers are specialized cardiac muscle cells that form a network of conducting fibers in the heart. They are responsible for the rapid and coordinated spread of electrical impulses from the atrioventricular node (AV node) to the ventricles, ensuring that the ventricles contract in a synchronized manner. Here are some key roles of Purkinje fibers in the heart:

1. Electrical Conduction: Purkinje fibers are specialized to conduct electrical impulses quickly and efficiently. They have a large diameter, fewer myofilaments, and reduced amounts of connective tissue compared to regular cardiac muscle cells, which allows for rapid propagation of electrical waves.

2. Synchronization of Ventricular Contraction: Purkinje fibers form a network that distributes electrical impulses throughout the ventricles. This network ensures that the electrical impulses reach all parts of the ventricles simultaneously, leading to a coordinated contraction of the entire ventricular muscle mass.

3. Speed and Velocity of Impulse Propagation: The Purkinje fibers conduct impulses at a much faster rate compared to the surrounding myocardial cells. This high conduction velocity ensures that the electrical signals are transmitted rapidly from the AV node to the ventricles, allowing for a prompt and efficient ventricular contraction.

4. Insulation of the AV Valves: Purkinje fibers are located in close proximity to the AV valves, and they help to electrically isolate the atria from the ventricles. This insulation prevents the electrical signals from traveling back into the atria, which could cause abnormal heart rhythms.

5. Integration of Electrical Signals: Purkinje fibers receive electrical impulses from the AV node and integrate these signals to ensure that the ventricles contract at the appropriate rate and rhythm.

Overall, Purkinje fibers play a critical role in ensuring the proper electrical conduction and synchronization of ventricular contraction, which is essential for the efficient and coordinated pumping action of the heart.