purkinje network: a network of Purkinje fibers that carry the cardiac impulse from the atrioventricular node to the ventricles of the heart and causes them to contract
cardiac muscle: the muscle tissue of the heart; adapted to continued rhythmic contraction
virgin birth: the theological doctrine that Jesus Christ had no human father; Christians believe that Jesus's birth fulfilled Old Testament prophecies and was attended by miracles; the Nativity is celebrated at Christmas