ANATOMY

Detailed explanation-1: -Your Purkinje fibers are in the subendocardial surface of your ventricle walls. The subendocardial surface is part of the endocardium, the inner layer of tissue that lines your heart’s chambers. When the Purkinje fibers deliver electrical signals to your ventricles, the ventricles contract.

Detailed explanation-2: -The SA node starts the sequence by causing the atrial muscles to contract. That’s why doctors sometimes call it the anatomical pacemaker. Next, the signal travels to the AV node, through the bundle of HIS, down the bundle branches, and through the Purkinje fibers, causing the ventricles to contract.

Detailed explanation-3: -Purkinje fibers allow the heart’s conduction system to create synchronized contractions of its ventricles, and are essential for maintaining a consistent heart rhythm. The QRS complex is the large peak.

Detailed explanation-4: -Purkinje fibres are specialized sets of cells that conduct the passage of action potentials to the apex of the heart, ensuring not only a rapid but also a spatially and temporally co-ordinated spread of excitation across both ventricles.

Detailed explanation-5: -Action potentials propagate within the thin Purkinje fiber bundles from the base to the apex before activation of the surrounding myocytes occurs. Purkinje myocytes have less well-developed transverse tubules (seeeFig. 34.5B), which reduces membrane capacitance and thus accelerates action potential propagation.