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 theseRelated 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: