Final answer:
The intrinsic rate of the Purkinje fibers is 15-20 impulses per minute, which is the slowest rate in the heart's conduction system, responsible for coordinating efficient ventricular contractions.
Step-by-step explanation:
The intrinsic rate of the Purkinje fibers is the rate at which they can fire impulses independently, without influence from the sympathetic or parasympathetic nervous systems. These fibers are part of the heart's conduction system, and they innately discharge at a rate of 15-20 impulses per minute. It is important to note that the intrinsic rates vary as you move through the cardiac conduction system, with the SA node having the highest inherent rate of around 80-100 beats per minute, followed by other components like the AV node at 40-60 beats per minute, and the bundle branches at 20-30 beats per minute. The Purkinje fibers inherently have the slowest rate among these components. They are crucial in coordinating the contraction of the ventricles, ensuring the blood is efficiently pumped out of the heart into the systemic and pulmonary circulations.