Mass of self-excitatory nodal fibres in mammalian heart is represented by: Circulatory System Physiology Mcqs February 26, 2019 BILAL KHATTAK0 A.SA-Node B.Semilunar valves at the entrances of main aortae C.Bicuspid and tricuspid valves D.None of these Related Mcqs: Principle pacemaker in mammalian heart is: Pulse is defined as: Which of these structures is respobsible for conducting heart beat in rabbit’s heart: Heart beat in man is initiated by: Node of Tawara in rabbit’s heart is: Which of these are conducting elements in the heart of mammals: Heart beat is conducted by a nodal tissue made up of specialized muscles called: Heart of frog differs that of rabbit by presence of: Which of these nerve fibres accelerate the rate of heart beat: Bundle of His in mammalian heart extends through: