Question

With reference to working of heart, complete the analogy.
Pace setter : \(\underline{x}\) :: Pacemaker : \(y-\)

• A. x- AV node y- SA node
• B. x- SA node y- AV node
• C. x- SA node y- Bundle of His
• D. x- Bundle of His y- SA node

Hint:

Identify which node is called the pacemaker and which one passes on and delays the impulse.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
The cardiac conduction system has the SA node, the AV node and the bundle of His.

Step 2: Assign the terms
The SA node fires at the highest natural rate and starts each beat, so it is the pacemaker (y).
The AV node receives the impulse, delays it and passes it on, so it is the pace setter (x).

Step 3: Compare the options
Only the first option gives x as the AV node and y as the SA node.

Final Answer:
x is the AV node and y is the SA node. \[ \boxed{\text{(A) }\text{x - AV node, y - SA node}} \]