Final answer:
The specialized electrical conducting fibres in the heart are known as the Purkinje fibers, which are essential for spreading electrical impulses to the ventricular muscles and ensuring coordinated contractions.
Step-by-step explanation:
The specialized electrical conducting fibres in the heart are called the Purkinje fibers.
These are part of the conduction system of the heart, which also includes the sinoatrial node (SA node), internodal pathways, atrioventricular node (AV node), atrioventricular bundle (bundle of His), and the left and right bundle branches.
The Purkinje fibers play a crucial role by spreading the impulse to the myocardial contraction fibers of the ventricles, allowing for a coordinated contraction starting from the apex of the heart and moving towards the base, effectively pumping blood into the aorta and pulmonary trunk.