What is AV node is situated in ? and explain in detail?
Ans. is 'c' i.e., Koch's triangle AV node is situated in triangular pa (triangle of Koch) in the lower pa of interatrial septum. Triangle of Koch is landmark for AV node with its transition zone. It is bounded by tendon of todaro (superiorly), tricuspid valve septal leaflet (inferiorly) and coronary sinus orifice (basally). Conducting system Location in hea SA node Upper end of crista terminalis, near opening of SVC AV node Triangle of Koch's (near interatrial septum) Bundle of his Membranous pa of interventricular septum RBB Right surface of interventricular septum LBB Left surface of interventricular septum