Purkinje fibres are –
**Core Concept**
Purkinje fibers are a critical component of the heart's electrical conduction system, playing a pivotal role in regulating cardiac rhythm. They are a type of specialized cardiac muscle cell responsible for transmitting electrical impulses from the atrioventricular (AV) node to the ventricles.
**Why the Correct Answer is Right**
Purkinje fibers have a unique electrophysiological property, allowing them to rapidly conduct electrical impulses with minimal delay. This is due to their large size, low resistance, and high capacitance, which enables them to act as a high-speed electrical conduit. The Purkinje fibers' electrical activity is synchronized with the AV node, ensuring a coordinated contraction of the ventricles.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the primary function of Purkinje fibers.
**Option B:** This option is incorrect because it is not a characteristic of Purkinje fibers.
**Option C:** This option is incorrect because it refers to a different cardiac structure.
**Clinical Pearl / High-Yield Fact**
Purkinje fibers are an essential part of the heart's electrical conduction system, and abnormalities in their function can lead to arrhythmias such as ventricular fibrillation.
**Correct Answer:** C. They are specialized cardiac muscle cells that transmit electrical impulses from the AV node to the ventricles.