What is the rate per minute for Purkinje Fibres?

Purkinje fibers are specialized conductive fibers located in the heart that play a crucial role in the electrical conduction system, particularly in initiating contraction of the ventricles. The intrinsic firing rate of Purkinje fibers is generally between 20 to 40 beats per minute. This slower rate is due to their role as backup pacemakers, taking over when the higher pacemaker cells, like the sinoatrial node and atrioventricular node, fail to initiate electrical impulses at a normal rate.

Understanding this rate is important because it highlights the responsiveness and adaptability of the heart's conduction system in maintaining cardiac function, especially under stress or in the presence of certain cardiac conditions. The other choices provided reflect the firing rates of the heart's primary pacemaking structures, such as the sinoatrial node (which typically fires at 60-100 beats per minute) and the atrioventricular node (which can fire at 40-60 beats per minute). This context emphasizes the unique role of Purkinje fibers within the heart's electrical system.