Question

'Heart of heart' is

• A. SA node
• B. AV node
• C. Bundle of His
• D. Purkinje fibres.

Answer 1

The correct option is A SA node

• The heart is a muscular organ made up of specialized muscles called cardiac muscles.
• These muscles show continuous contraction and relaxation.
• This contraction results from an electrical impulse that originates in a node called the sinoatrial, or SA node.
• This node is in the upper right corner of the right auricle and sets a rhythm for the contractions and relaxations of the heart.
  
• Hence, it is also referred to as a natural pacemaker or 'Heart of heart'.

So, the correct answer is option A.