Question

Pacemaker is situated in heart

• A. In the wall of right atrium
• B. On interauricular septum
• C. On interventricular septum
• D. In the wall of left atrium

Answer 1

The correct option is A In the wall of right atrium

Pace maker is Sinoatrial or SA node situated in the upper corner of wall of right atrium in heart. It initiates and maintains the rhythmic contraction of heart. Excitation waves begin in SA node due to which atria contract and the oxygenated and deoxygenated blood is forced into respective ventricles through atrioventricular valves. It acts as stimulus for the next wave of excitation and thus, maintains the frequency of heart beat.

So, the correct answer is 'In the wall of right atrium'.